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A measurement of the production of prompt Λ+c baryons in Pb-Pb collisions at sNN−−−√=5.02 TeV with the ALICE detector at the LHC is reported. The Λ+c and Λ¯¯¯¯−c were reconstructed at midrapidity (|y|<0.5) via the hadronic decay channel Λ+c→pK0S (and charge conjugate) in the transverse momentum and centrality intervals 6<pT<12 GeV/c and 0-80%. The Λ+c/D0 ratio, which is sensitive to the charm quark hadronisation mechanisms in the medium, is measured and found to be larger than the ratio measured in minimum-bias pp collisions at s√=7 TeV and in p-Pb collisions at sNN−−−√=5.02 TeV. In particular, the values in p-Pb and Pb-Pb collisions differ by about two standard deviations of the combined statistical and systematic uncertainties in the common pT interval covered by the measurements in the two collision system. The Λ+c/D0 ratio is also compared with model calculations including different implementations of charm quark hadronisation. The measured ratio is reproduced by models implementing a pure coalescence scenario, while adding a fragmentation contribution leads to an underestimation. The Λ+c nuclear modification factor, RAA, is also presented. The measured values of the RAA of Λ+c, Ds and non-strange D mesons are compatible within the combined statistical and systematic uncertainties. They show, however, a hint of a hierarchy (RD0AA<RDsAA<RΛ+cAA), conceivable with a contribution of recombination mechanisms to charm hadron formation in the medium.
A measurement of the production of prompt Λ+c baryons in Pb-Pb collisions at sNN−−−√=5.02 TeV with the ALICE detector at the LHC is reported. The Λ+c and Λ¯¯¯¯−c were reconstructed at midrapidity (|y|<0.5) via the hadronic decay channel Λ+c→pK0S (and charge conjugate) in the transverse momentum and centrality intervals 6<pT<12 GeV/c and 0-80%. The Λ+c/D0 ratio, which is sensitive to the charm quark hadronisation mechanisms in the medium, is measured and found to be larger than the ratio measured in minimum-bias pp collisions at s√=7 TeV and in p-Pb collisions at sNN−−−√=5.02 TeV. In particular, the values in p-Pb and Pb-Pb collisions differ by about two standard deviations of the combined statistical and systematic uncertainties. The Λ+c/D0 ratio is also compared with model calculations including different implementations of charm quark hadronisation. The measured ratio is reproduced by models implementing a pure coalescence scenario, while adding a fragmentation contribution leads to an underestimation. The Λ+c nuclear modification factor, RAA, is also presented. The measured values of the RAA of Λ+c, Ds and non-strange D mesons are compatible within the combined statistical and systematic uncertainties. They show, however, a hint of a hierarchy (RD0AA<RDsAA<RΛ+cAA), conceivable with a contribution of recombination mechanisms to charm hadron formation in the medium.
Λ+c production and baryon-to-meson ratios in pp and p–Pb collisions at √sNN = 5.02 TeV at the LHC
(2021)
The prompt production of the charm baryon Λ+c and the Λ+c/D0 production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sNN−−−√=5.02TeV. These new measurements show a clear decrease of the Λ+c/D0 ratio with increasing transverse momentum (pT) in both collision systems in the range 2<pT<12 GeV/c, exhibiting similarities with the light-flavour baryon-to-meson ratios p/π and Λ/K0S. At low pT, predictions that include additional colour-reconnection mechanisms beyond the leading-colour approximation; assume the existence of additional higher-mass charm-baryon states; or include hadronisation via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e+e− and e−p collisions significantly underestimate the data. The results presented in this letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.
Λ+c production and baryon-to-meson ratios in pp and p–Pb collisions at √sNN = 5.02 TeV at the LHC
(2021)
The prompt production of the charm baryon Λ+c and the Λ+c/D0 production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sNN−−−√=5.02TeV. These new measurements show a clear decrease of the Λ+c/D0 ratio with increasing transverse momentum (pT) in both collision systems in the range 2<pT<12 GeV/c, exhibiting similarities with the light-flavour baryon-to-meson ratios p/π and Λ/K0S. At low pT, predictions that include additional colour-reconnection mechanisms beyond the leading-colour approximation; assume the existence of additional higher-mass charm-baryon states; or include hadronisation via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e+e− and e−p collisions significantly underestimate the data. The results presented in this letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.
Λ+c production and baryon-to-meson ratios in pp and p–Pb collisions at √sNN = 5.02 TeV at the LHC
(2021)
The prompt production of the charm baryon Λ+c and the Λ+c/D0 production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sNN−−−√=5.02TeV. These new measurements show a clear decrease of the Λ+c/D0 ratio with increasing transverse momentum (pT) in both collision systems in the range 2<pT<12 GeV/c, exhibiting similarities with the light-flavour baryon-to-meson ratios p/π and Λ/K0S. At low pT, predictions that include additional colour-reconnection mechanisms beyond the leading-colour approximation; assume the existence of additional higher-mass charm-baryon states; or include hadronisation via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e+e− and e−p collisions significantly underestimate the data. The results presented in this letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.
Λ+c production and baryon-to-meson ratios in pp and p–Pb collisions at √sNN = 5.02 TeV at the LHC
(2020)
The prompt production of the charmed baryon Λ+c and the Λ+c/D0 production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sNN−−−√=5.02TeV. These new measurements show a clear decrease of the Λ+c/D0 ratio with increasing transverse momentum (pT) in both collision systems in the range 2<pT<12 GeV/c, exhibiting similarities with the light-flavour baryon-to-meson ratios p/π and Λ/K0S. At low pT, predictions that include additional colour-reconnection mechanisms beyond the leading-colour approximation; assume the existence of additional higher-mass charmed-baryon states; or include hadronisation via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e+e− and e−p collisions significantly underestimate the data. The results presented in this letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charmed-baryon production in hadronic collisions at LHC energies.
In April and May 2012 data on Au+Au collisions at beam energies of Ekin = 1.23A GeV were recorded with the High Acceptance Di-Electron Spectrometer, which is located at the GSI Helmholtz Center for Heavy Ion Research in Darmstadt, Germany. At this beam energy all hadrons containing strangeness are produced below their elementary production threshold. The required energy is not available in binary NN collisions but must be provided by the system e.g. through multi-particle interactions or medium effects like a modified in-medium potential (e.g. KN/ΛN potential). Thus, a high sensitivity to these medium effects is expected in the investigated system.
The baryon-dominated systems created in relativistic heavy-ion collisions (HIC) at SIS18 energies reach densities of about 2-3 times ground state density p0 and may be similar to the properties of matter expected in the inner core of neutron stars. It is in particular the behavior of hadrons containing strangeness, i.e. kaons and hyperons, and their potentials in the dense medium which may have severe implications on astrophysical objects and processes. As ab-initio calculations of quantum chromodynamics (QCD) cannot be performed rigorously on the lattice at finite baryo-chemical potentials due to the fermion sign problem, effective descriptions have to be used in order to model properties of dense systems and the involved particles. The only way to access the in-medium potential of strange hadrons above nuclear ground state density p0 is by comparing data from relativistic HIC to such effective microscopic models. Up to now, not much data on neutral kaons and Λ hyperons are available from heavy collision systems close to their NN production threshold. These two electromagnetically uncharged strange hadrons are in particular well suited to study their potential in a dense nucleon-dominated environment as their kinematic spectra are not affected by Coulomb interactions.
Although, during the past decades, substantial advances emerged in identifying major local and systemic factors contributing to initiation and progression of osteoarthritis (OA), some neuroendocrine mechanisms are still not understood or even neglected when thinking about novel therapeutic options. One of which is the sympathetic nervous system that exhibits various OA-promoting effects in different tissues of the joint. Interestingly, the β2-adrenoceptor (AR) mediates the majority of these effects as demonstrated by several in vitro, in vivo as well as in clinical studies. This review article does not only summarize studies of the past two decades demonstrating that the β2-AR plays an OA-promoting role in different tissues of the joint but also aims to encourage the reader to think about next-level research to discover novel and innovative preventive and/or therapeutic strategies targeting the β2-AR in OA.
Purpose: Recent studies demonstrated a contribution of adrenoceptors (ARs) to osteoarthritis (OA) pathogenesis. Several AR subtypes are expressed in joint tissues and the β2-AR subtype seems to play a major role during OA progression. However, the importance of β2-AR has not yet been investigated in knee OA. Therefore, we examined the development of knee OA in β2-AR-deficient (Adrb2-/-) mice after surgical OA induction.
Methods: OA was induced by destabilization of the medial meniscus (DMM) in male wildtype (WT) and Adrb2-/- mice. Cartilage degeneration and synovial inflammation were evaluated by histological scoring. Subchondral bone remodeling was analyzed using micro-CT. Osteoblast (alkaline phosphatase - ALP) and osteoclast (cathepsin K - CatK) activity were analyzed by immunostainings. To evaluate β2-AR deficiency-associated effects, body weight, sympathetic tone (splenic norepinephrine (NE) via HPLC) and serum leptin levels (ELISA) were determined. Expression of the second major AR, the α2-AR, was analyzed in joint tissues by immunostaining.
Results: WT and Adrb2-/- DMM mice developed comparable changes in cartilage degeneration and synovial inflammation. Adrb2-/- DMM mice displayed elevated calcified cartilage and subchondral bone plate thickness as well as increased epiphyseal BV/TV compared to WTs, while there were no significant differences in Sham animals. In the subchondral bone of Adrb2-/- mice, osteoblasts activity increased and osteoclast activity deceased. Adrb2-/- mice had significantly higher body weight and fat mass compared to WT mice. Serum leptin levels increased in Adrb2-/- DMM compared to WT DMM without any difference between the respective Shams. There was no difference in the development of meniscal ossicles and osteophytes or in the subarticular trabecular microstructure between Adrb2-/- and WT DMM as well as Adrb2-/- and WT Sham mice. Number of α2-AR-positive cells was lower in Adrb2-/- than in WT mice in all analyzed tissues and decreased in both Adrb2-/- and WT over time.
Conclusion: We propose that the increased bone mass in Adrb2-/- DMM mice was not only due to β2-AR deficiency but to a synergistic effect of OA and elevated leptin concentrations. Taken together, β2-AR plays a major role in OA-related subchondral bone remodeling and is thus an attractive target for the exploration of novel therapeutic avenues.
No disease modifying therapy is currently available for Parkinson’s disease (PD), the second most common neurodegenerative disease. The long non-motor prodromal phase of PD is a window of opportunity for early detection and intervention. However, we lack the pathophysiological understanding to develop selective biomarkers and interventions. By developing a mutant α-synuclein selective-overexpression mouse model of prodromal PD, we identified a cell-autonomous selective Kv4 channelopathy in dorsal motor nucleus of the vagus (DMV) neurons. This functional remodeling of intact DMV neurons leads to impaired pacemaker function in vitro and in vivo, which in turn reduces gastrointestinal motility which is a common, very early symptom of prodromal PD. We show for the first time a causal chain of events from α-synuclein via a biophysical dysfunction of specific neuronal populations to a clinically relevant prodromal symptom. These findings can facilitate the rational design of clinical biomarkers to identify people at risk for PD.
α-ketoglutarate dehydrogenase inhibition counteracts breast cancer-associated lung metastasis
(2018)
Metastasis formation requires active energy production and is regulated at multiple levels by mitochondrial metabolism. The hyperactive metabolism of cancer cells supports their extreme adaptability and plasticity and facilitates resistance to common anticancer therapies. In spite the potential relevance of a metastasis metabolic control therapy, so far, limited experience is available in this direction. Here, we evaluated the effect of the recently described α-ketoglutarate dehydrogenase (KGDH) inhibitor, (S)-2-[(2,6-dichlorobenzoyl) amino] succinic acid (AA6), in an orthotopic mouse model of breast cancer 4T1 and in other human breast cancer cell lines. In all conditions, AA6 altered Krebs cycle causing intracellular α-ketoglutarate (α-KG) accumulation. Consequently, the activity of the α-KG-dependent epigenetic enzymes, including the DNA demethylation ten-eleven translocation translocation hydroxylases (TETs), was increased. In mice, AA6 injection reduced metastasis formation and increased 5hmC levels in primary tumours. Moreover, in vitro and in vivo treatment with AA6 determined an α-KG accumulation paralleled by an enhanced production of nitric oxide (NO). This epigenetically remodelled metabolic environment efficiently counteracted the initiating steps of tumour invasion inhibiting the epithelial-to-mesenchymal transition (EMT). Mechanistically, AA6 treatment could be linked to upregulation of the NO-sensitive anti-metastatic miRNA 200 family and down-modulation of EMT-associated transcription factor Zeb1 and its CtBP1 cofactor. This scenario led to a decrease of the matrix metalloproteinase 3 (MMP3) and to an impairment of 4T1 aggressiveness. Overall, our data suggest that AA6 determines an α-KG-dependent epigenetic regulation of the TET–miR200–Zeb1/CtBP1–MMP3 axis providing an anti-metastatic effect in a mouse model of breast cancer-associated metastasis.
Es werden Schwingkreismodelle angegeben, deren Säkulargleichungen mit denen formal identisch sind, die sich bei der Anwendung der Methode der Moleküleigenfunktionen auf das Problem der π -Elektronenzustände in Molekülen ungesättigter und aromatischer Kohlenwasserstoffe ergeben. Damit ergibt sich die Möglichkeit, die quantenmechanischen Säkularprobleme durch Messung der Eigenfrequenzen der Modelle zu bestimmen.
1. Electron micrographs of ultra-thin sections of Staphylococcus aureus and Micrococcus lysodeikticus in Vestopal as embedding medium disclose a multiplicity of DNA containing threads with varying interparticular distances.
2. The diameter of these threads is about one tenth of the average optimal section thickness.
3. This section thickness inevitably is implicated in the visualization of the internal distances between the threads as well as in some common trends in the DNA pool, a fact that has to be accounted for in the analysis of the macromolecules.
4. By spreading lysozyme protoplasts of M. lysodeikticus on a water-air interface in a Langmuir trough and by transferring this surface layer to carbon supported Formvar films, two-dimensional systems can be demonstrated which as a thread of constant width comprise the total DNA content of one microorganism each.
5. Such a macromolecular system shows equally shaped, coiled loops in a peripheral zone and many crossings towards the center. Branching of threads never has been observed so far.
From this evidence we conlude:
a) Intracellular DNA in these bacteria seems to exist in one pool as a “woolen ball” which is centered in the cytoplasm as a more or less dense object.
b) This “woolen ball“ embodies the total amount of DNA most probably as one single threadlike unit.
6. Partial destruction of the thread system of protoplasts will result upon changing optimal spreading conditions.
7. The same kind of destruction is shown upon isolation of the DNA from protoplasts, the length of the threads being an inverse function of the number of precipitation steps showing purification.
ß-Hydroxybutyrate (BHB) is a ketone body formed in high amounts during lipolysis and fasting. Ketone bodies and the ketogenic diet were suggested as neuroprotective agents in neurodegenerative disease. In the present work, we induced transient ischemia in mouse brain by unilaterally occluding the middle cerebral artery for 90 min. BHB (30 mg/kg), given immediately after reperfusion, significantly improved the neurological score determined after 24 h. In isolated mitochondria from mouse brain, oxygen consumption by the complexes I, II and IV was reduced immediately after ischemia but recovered slowly over 1 week. The single acute BHB administration after reperfusion improved complex I and II activity after 24 h while no significant effects were seen at later time points. After 24 h, plasma and brain BHB concentrations were strongly increased while mitochondrial intermediates (citrate, succinate) were unchanged in brain tissue. Our data suggest that a single administration of BHB may improve mitochondrial respiration for 1–2 days but not for later time points. Endogenous BHB formation seems to complement the effects of exogenous BHB administration.
Alzheimer’s Disease (AD) is the most common neurodegenerative disorder marked by progressive loss of memory and cognitive ability. The pathology of AD is characterised by the presence of amyloid plaques, intracellular neurofibrillary tangles and pronounced cell death. The aim of this thesis was to investigate pathways involved in the Aß cascade of neurodegeneration. Since novel findings indicate that already this Aß species exerts neurotoxic effects long before hyperphosphorylated tau, neurofibrillary tangles and extracellular Aß plaques appear, the investigations were accomplished with specific regard to the effects of intracellular Aß. The Swedish double mutation in the APP gene results in six- to eightfold increased Aß production of both Aß1-40 and Aß1-42 compared to human wildtype APP cells (APPwt). Data obtained from PC12 cells indicate that it is possible to specifically increase the Aß load without enhancing APP expression levels. On the basis of these findings, it seemed possible to investigate dose-dependent effects of Aß in multiple experimental designs. These assay designs were created in order to mimick different in-vivo situations that are discussed to occur in AD patients: APPsw PC12 cells exhibit low physiological concentrations of Aß within picomolar range in contrast to APPsw HEK cells, expressing Aß levels within the nanomolar range. Of note, the APPsw HEK cells showed a specific and highly significant increase in the intracellular accumulation of insoluble Aß1-42. Moreover, an intracellular accumulation of Aß and APP was found in the mitochondria of the HEK APPsw cells suggesting a direct impact on mitochondrial function on these cells. This effect might finally lead to disturbances in the energy metabolism of the cell or to increased cell death. Furthermore, baseline g- and ß-secretase activity was assessed since these enzymes represent promising therapeutic targets to slow or halt the disease process. As expected, ß-secretase activity was significantly elevated in all APPsw cell lines. This might be due to the proximity of the Swedish double mutation next to the N-terminus of the Aß sequence. Interestingly, g-secretase activity was similarly increased in PC12 APPsw cells. In addition, the toxicity of different Aß species was investigated in SY5Y and PC12 cells with regard to their effect on cellular viability mirrored by mitochondrial activity using MTT assay. Here, it turned out that not monomers, but already dimers are neurotoxic correlates. Fibrillar Aß species showed the highest toxicity. In the next step, SY5Y cells forming endogenous, dimeric APP and Aß were investigated. In accordance with previous findings, these cells showed a decreased MTT reduction potential in comparison to APPwt and control SY5Y cells reflecting a decrease of cellular viability. The impaired energy metabolism of the cells was even more drastically mirrored by reduced baseline ATP levels. In the second part of this thesis, the expression and intracellular distribution of Bcl-2 family proteins and pro-apoptotic mitochondrial factors under baseline conditions and during oxidative stress were analyzed in the APPwt and APPsw bearing cells. The most prominent finding was the reduction of expression levels of the anti-apoptotic factor Bcl-xL in the cytosolic fractions of APPwt and APPsw PC12 cells. This might indicate that a lack of anti-apoptotic factors or their altered intracellular distribution, rather than an increase in caspase-dependent pro-apoptotic factors, could be responsible for the increased vulnerability of APPwt- and APPsw-transfected PC12 cells against oxidative stress. Since total Bcl-xL expression was unaffected in PC12 cells, in contrast to APPwt and APPsw-expressing SY5Y and HEK cells revealing significantly decreased Bcl-xL expression levels. Thus, alterations in Bcl-xL distribution seem to be an early event in the disease process. Increasing Bcl-xL expression might potentially be one promising strategy for AD modification. PC12 and HEK cells bearing APPsw or APPwt were treated with the potent g-secretase inhibitor DAPT. Of note, DAPT did not only efficiently block Aß production, but additionally led to an elevation of the MTT reduction potential, reflecting an increase in cellular viability. As another disease-modifying strategy, several efforts are undertaken to ameliorate AD-relevant symptoms by the treatment with nerve growth factor (NGF). Generally, it is known that substituted pyrimidines have modest growth-promoting effects. Here, KP544, a novel substituted pyrimidine, was characterised. This drug increased MTT reduction potential in terminally differentiated and undifferentiated PC12 cells. Furthermore, treatment with KP544 led to a reduction in Aß1-40 secretion. Thus, one may conclude that the target of KP544, GSK-3ß, represents a connecting link between the two main pathological hallmarks of AD and might thus be a very promising therapeutic target for AD.
In 2014, 56 localities in four provinces of Lesser Himalaya in Pakistan were studied. A total of 28 species have been recorded. A female of the data deficient, threatened species Coeliccia vacca was recorded from Charhaan. The record of Drepanosticta carmichaeli is a new addition to the list of Odonata of Pakistan, and expand the range of this species further to the west. The taxonomical status of Ischnura aurora aurora – considered common in Pakistan, following baseline literature of Fraser (1933) – now turns out to be Ischnura aurora rubilio.
Zvi Keren: his contribution to Israel's music scene : an interview in honor of his 85th birthday
(2002)
It is with great pride that I introduce a new section in this issue of Min-Ad: Israel Studies in Musicology, dedicated to interviews with musicians who have made major contributions to Israel’s music life. I am particularly pleased to inaugurate this section with an interview with our esteemed colleague (and in my case, teacher), Zvi Keren, a major figure in the development of Israel´s contemporary, jazz and light music. This interview is conducted by Alona Keren-Sagee, Zvi Keren´s daughter.
The Polyzoa discussed or described in this paper are all from fresh or brackish water. The majority are from the Tale Sap in the north-eastern part of the Malay Peninsula} but a few come from the Tai-Hu in the Kiangsu Province of China. I have also included notes on one Indian form. The following species are to be considered: ENTOPROCTA. Chitaspis athleticus, gen. et sp. nov., from the Tale Sap. CTENOSTOMATA. Alcyonidium mytili, Dalyell, from Indian estuaries, etc. Triticella pediceltata (Alder), from the Tale Sap. Bowerbankiacaudata, Hincks, from the Tale Sap and Perak. Paludicella elongata, Leidy, from the Tai-Hu. Paludicella pentagonalis, sp. nov., from the Tale Sap. Victorelta bengalensis, Annandale, from the Tale Sap. Hislopia cambodgiensis (Jullien), from the Tai-Hu. Hislopia malayensis. sp. nov., from Jalor in the Malay Peninsula. It will be as well to defer consideration of the biology and distribution of these species until I have been able to deal systematically with the Phylactolaemata and Cheilostomata collected on my tour. All that need be said here is that while the species of Paludicella and Hislopia are from fresh water, the others. on the list are from brackish water.
The genus Rhagovelia is revised for the region comprising Borneo, Celebes, and the Moluccas. Redescriptions are given for species previously described from the area, and 26 new species are described. Figures of the dorsal habitus and key characters are provided for all species, accompanied by a key to species and distribution maps. Species occurring in the region are divided into eight monophyletic intrageneric species groups, some of which also contain members outside the region, based primarily on wing venation, thoracic morphology, and genitalia. A zoogeographic analysis is presented based on the distribution of these groups within the Malay Archipelago and surrounding regions. We conclude that the present Rhagovelia fauna of the Malay Archipelago is derived from species which originated in continental Southeast Asia, Australia, and New Caledonia. Distinct lineages have entered the region from each of these three source areas, penetrating the archipelago with differing degrees of success and contributing to the fauna of each individual island to varying extents. Species groups of Asian origin do not extend beyond Celebes and the Lesser Sunda islands, while species groups of Papuan origin are absent in the Lesser Sundas and do not extend west of Borneo. Endemic species groups have also arisen on New Guinea, the Philippines, the north Moluccas, and Borneo. A section on ecology and behavior is provided, dealing in particular with the altitudinal segregation of species on individual islands. The following new Rhagovelia species are described: bacanensis, borneensis, celebensis, christenseni, grayi, hamdjahi, incognita, lorelinduana, meikdelyi, melanopsis, minahasa, obi, pruinosa, ranau, sabela, samardaca, samarinda, sarawakensis, silau, simulata, sondaica, sulawesiana, tawau, lebakang, unica, and wallacei. Rhagovelia mindanaoensis Hungerford and Matsuda 1961 is synonymized with Rhagovelia orientalis Lundblad 1937 (new synonymy).
Four species of mole crickets (Orthoptera: Gryllotalpidae) are known from the West Indies: Neocurtilla hexadactyla (Perty), Scapteriscus abbreviatus Scudder, S. didactylus (Latreille), and S. imitatus Nickle and Castner. All are adventive (not native). We document their distributions in West Indian islands/countries by use of records from the literature and examination of specimens. Scapteriscus abbreviatus has been suggested to have arrived in, and been transported about the West Indies in ship ballast (immigration). Based on records of arrival in various parts of the West Indies and the species’ inability to fly, this suggestion seems reasonable. Scapteriscus imitatus pparently was released in Puerto Rico as a result of mistaken identification (introduction – arriving with assistance from humans – although inadvertent), and has not expanded its range in the West Indies. Although the principal mode of dispersal for the other two species also has been suggested to be ship ballast, we present an alternative based on flight which would seem at least equally as plausible. We suggest that S. didactylus could have dispersed by flight from South America through the Lesser Antilles; likewise N. hexadactyla probably from the Yucatan Peninsula to Cuba, and from South America northward through the Lesser Antilles, in at least some localities assisted by wind. Our zoogeographical alternative, if correct, means that the natural range expansions of these latter two species began very long ago and without human assistance – they were not introduced recently to the West Indies.
Zinc finger proteins (ZNF) are a large group of transcription factors with diverse functions. We recently discovered that endothelial cells harbour a specific mechanism to limit the action of ZNF354C, whose function in endothelial cells is unknown. Given that ZNF354C has so far only been studied in bone and tumour, its function was determined in endothelial cells. ZNF354C is expressed in vascular cells and localises to the nucleus and cytoplasm. Overexpression of ZNF354C in human endothelial cells results in a marked inhibition of endothelial sprouting. RNA-sequencing of human microvascular endothelial cells with and without overexpression of ZNF354C revealed that the protein is a potent transcriptional repressor. ZNF354C contains an active KRAB domain which mediates this suppression as shown by mutagenesis analysis. ZNF354C interacts with dsDNA, TRIM28 and histones, as observed by proximity ligation and immunoprecipitation. Moreover, chromatin immunoprecipitation revealed that the ZNF binds to specific endothelial-relevant target-gene promoters. ZNF354C suppresses these genes as shown by CRISPR/Cas knockout and RNAi. Inhibition of endothelial sprouting by ZNF354C is dependent on the amino acids DV and MLE of the KRAB domain. These results demonstrate that ZNF354C is a repressive transcription factor which acts through a KRAB domain to inhibit endothelial angiogenic sprouting.
The following pages, initially prepared for limited circulation in 1961, contain brief extracts and summaries of those parts of Eugen ZintgraffÍs book Nord-Kamerun (1895), of most interest concerning the colonial Bamenda and Wum Division. ZintgraffÍs book, the first by a European about the Grassfields, has not been translated and is hard to get second-hand. In using these notes the following points should be borne in mind: ZintgraffÍs knowdie;ledge of Bali (Mungaka) and Hausa was very slight, and his discussions of character, motives and political institutions are consequently superficial and open to criticisms. He had no means of checking what he was told, or thought he was told. He had no previous knowledge of any similar culture and no training in ethnographical method. He was, however, a good observer, and his descriptions of tools, dress, weapons and the like, can be regarded as fairly reliable. Finally, it must be remembered that Zintgraff wrote the book to justify his own actions and to support that small but influential section of public opinion in Germany which favoured rapid imperial expansion. A full account of the actions and motives of ZintgraffÍs opponents in the Kamerun Governdie;ment and in the Colonial Bureau of the German Foreign Office has not been written: we only have one side of the story. But there are some suggestive points made in RudinÍs Germans in the Cameroons and others referred to in these notes. What is perhaps most striking about ZintgraffÍs account is the fact that the people of the Western Grassfields were not so isolated from one another or their neighbours as might be thought. A network of trade-friendships covered the country and big men exchanged gifts over long distances. These links must be set beside the insedie;curity due to raids and slave-catching, and are well worth investigation.
Iron deficiency (ID) is a common manifestation of inflammatory bowel disease (IBD), arising primarily due to chronic inflammation and/or blood loss. There is no gold standard for ID diagnosis, which is often complicated by concomitant inflammation. Zinc protoporphyrin (ZnPP) correlates with parameters of iron homeostasis and has been identified as a promising marker for ID, irrespective of inflammation. We investigated the diagnostic performance of ZnPP in ID, iron deficiency anemia, anemia of chronic disease and mixed anemia in a cross-sectional study in 130 patients with IBD. Different parameters were compared by receiver operator characteristic (ROC) analysis as detectors of iron-restricted erythropoiesis (IRE). IRE was detected in 91 patients (70.0%); fifty-nine (64.8%) had absolute ID and 23 (25.4%) functional ID. When inflammation was present, ZnPP was a more reliable sole biomarker of IRE than MCV, transferrin saturation (TSAT) or ferritin (AUC; 0.855 vs. 0.763, 0.834% and 0.772, respectively). The specificity of TSAT was significantly lower than ZnPP when inflammation was present (38% vs. 71%, respectively). We conclude that ZnPP is a reliable biomarker of functional ID in patients with IBD and more dependable than ferritin or TSAT, which are influenced by chronic inflammation. We propose that ZnPP may also have utility in patients with other chronic diseases.
The traffic AAA-ATPase PilF is essential for pilus biogenesis and natural transformation of Thermus thermophilus HB27. Recently, we showed that PilF forms hexameric complexes containing six zinc atoms coordinated by conserved tetracysteine motifs. Here we report that zinc binding is essential for complex stability. However, zinc binding is neither required for pilus biogenesis nor natural transformation. A number of the mutants did not exhibit any pili during growth at 64 °C but still were transformable. This leads to the conclusion that type 4 pili and the DNA translocator are distinct systems. At lower growth temperatures (55 °C) the zinc-depleted multiple cysteine mutants were hyperpiliated but defective in pilus-mediated twitching motility. This provides evidence that zinc binding is essential for the role of PilF in pilus dynamics. Moreover, we found that zinc binding is essential for complex stability but dispensable for ATPase activity. In contrast to many polymerization ATPases from mesophilic bacteria, ATP binding is not required for PilF complex formation; however, it significantly increases complex stability. These data suggest that zinc and ATP binding increase complex stability that is important for functionality of PilF under extreme environmental conditions.
Poetry is fragments of music thrown into the air. The primary job and aim of a poet is to create these musical notes, to play these musical notes, and the wind will take these fragment notes, sounds, musics into the ears of listeners. Zimbolicious Poetry Anthology, Volume 2 is one of those winds among many others. As we all are aware of, when the wind travels it has no boundaries, it collects, it deposits, it mixes things up; you never know where that leaf you see the wind carrying will eventually be deposited, is there another wind, another element that is going to move that leaf to another place... We firmly believe it is a good wind. It will be able to push our poetry making in Zimbabwe into other frontiers. Zimbolicious Poetry Anthology, Volume 2 continues from where we left off with the first Zimbolicious Poetry Anthology we created in 2016. In this Volume 2, we have 77 poems from 30 poets and translators, which include among others; experienced poets, academic poets, street poets, emergent poets, beginning poets, all telling stories associated with what all these poets refer to as home, that is, Zimbabwe. It is an ongoing debate on what is Zimbabwe, what we want our Zimbabwe to be socially, culturally, politically, thus we allowed every opinion space in this anthology, whether us editors agree with them or not. We have poets tackling issues to do with poetry, writing in general, art, place, identity, tradition, struggle, culture, gender, collective understanding, religion, individual, human rights and love, among others.
Zimbabwe: The Urgency of Now
(2015)
Zimbabwe: The Urgency of Now, is a follow-up creative non-fiction book to Zimbabwe: The Blame Game. It goes further than The Blame Game and focuses on Zimbabwe in the GNU entity, the 2013 elections, post elections and post GNU Zimbabwe, and Now. They are a myriad number of problems, issues, limitations that still unbundles Zimbabwe's push towards multiparty democracy, social justice, economic sanity and growth, and The Urgency of Now focuses on the solutions to these. It also tackles the land reform in South Africa, how this could be its biggest problem going forward. It goes further and tackles the larger Africa problem toward democracy, growth, stability and unity, and why the progress towards the United States of Africa has been moribund.
Zimbabwe: The Blame Game
(2013)
The Blame Game is a cycle of creative non-fiction pieces, pulling the readers through the politics of modern day Zimbabwe. Like in any game, there are players in this game, opposing each other. The game is told through the eyes of one of the players, thus it is subjective. It centres on truthfully trying to find who to blame for Zimbabwe's problems, and how to undo all these problems. Finding who to blame should be the beginning for the search of solutions. It encourages talking to each other, maybe about the wrongs we have done to each other, and genuinely trying to embrace and forgive each other. In trying to undo the problems in Zimbabwe, it also offers insight or solutions on a larger platform - Africa: particularly South Africa; that it might learn from other African countries that have imploded before it, how to solve its own problems.
Three years after the advent of Zimbabwe's Inclusive Government in February 2009, the country still awaits the elections that people hope will lead to a more enduring political settlement. Zimbabwe: Mired in Transition reviews the experience of recent years assesses the progress that has been made. What is the public mood, and how has it changed? What steps have been taken to reform the media? How important is a new constitution. Although the economy has stabilised to some extent with the adoption of a multi-currency regime, industrial and agricultural production are depressed, and investment inflows are limited; what spaces exist for fiscal reform? Are local authority structures and the state bureaucracy equipped to handle the tasks that will ne asked of them? In terms of two important areas, the book extends its analysis further back than 2009. First, is the issue of emigration. Estimates of the number of Zimbabweans in the diaspora range from three to four million; what impact us this having on national development, and to what extent might the trend of migration be reversed? The second concerns young people, the chapter on which concludes: 'We already have a 'lost generation' - those who were once called the 'born frees'. Unless positive changes are made, we will still have another'. This collection of eleven essays examines in detail some of the pressing questions which Zimbabweans must ask as they chart a way forward.
At Independence in 1980, Julius Nyerere called Zimbabwe 'the jewel of Africa', and cautioned its new leaders not to tarnish it. Tragically, they paid no heed to Africa's esteemed elder statesmen. Arguably - and only if one ignores the carnage of Gukurahundi - the first decade was a developmental one, with resources being used prudently to benefit the formerly disadvantaged majority population. However, the 1990s witnessed a transition from a developmental to a predatory leadership which saw Zimbabwe cross the millennial line in crisis, where it has remained ever since. While many African countries have moved forward over the last three decades, Zimbabwe has gone relentlessly backwards, save for the four-year interregnum of the tripartite coalition government, 2009-2013. Virtually all development indicators point in the wrong direction and the crisis of poverty, unemployment, and the erosion of health. education and other public goods continues unabated. The imperatives of political survival and power politics supersede those of sound economics and public welfare. Moreover, unless good politics are conjoined with a sound people-first policy, the country will continue sliding downhill. Zimbabwe's Trajectory tells the story of the country's post-independence dynamics and its recent descent into becoming one of the three most unhappy countries in the world.
The ongoing crisis in Zimbabwe has led to an unprecedented exodus of over a million desperate people from all strata of Zimbabwean society. The Zimbabwean diaspora is now truly global in extent. Yet rather than turning their backs on Zimbabwe, most maintain very close links with the country, returning often and remitting billions of dollars each year. Zimbabwe's Exodus. Crisis, Migration, Survival is written by leading migration scholars many from the Zimbabwean diaspora. The book explores the relationship between Zimbabwe's economic and political crisis and migration as a survival strategy. The book includes personal stories of ordinary Zimbabweans living and working in other countries, who describe the hotility and xenophobia they often experience.
Zimbabwe's Cultural Heritage
(2005)
' Zimbabwe's Cultural Heritage won first prize in the Zimbabwe Book Publishers Association Awards in 2006 for Non-fiction: Humanities and Social Sciences. It is a collection of pieces of the culture of the Ndebele, Shona, Tonga, Kalanga, Nambiya, Xhosa and Venda. The book gives the reader an insight into the world view of different peoples, through descriptions of their history and life events such as pregnancy, marriage and death. ''...the most enduring book ever on Zimbabwean history. This book will help people change their attitude towards each other in Zimbabwe.'' - Zimbabwe Book Publishers Association Awards citation'
Zimbabwe Will Never be a Colony Again! : Sanctions and Anti-Imperialist Struggles in Zimbabwe
(2019)
This is a thought-provoking original book, based on a wealth of empirical case studies of how Zimbabwe experienced illegal economic sanctions. It is a study of how the humanly constructed obstructions - from external remittances/finance flows into the country to finance embargos or total financial blockages - are deliberately created by so-called 'powerful' governments to deal with an 'errand' country. The infamous Zimbabwe Democracy Economic Recovery Act of 2001 (ZDERA) is part of a raft of punitive measures and discourses that the USA, UK and Europe used to make the economy, in the words of US's Chester Crooker 'scream'. It is the same 'powerful' countries who allow their Multinational Corporations to loot while they impose sanctions against African governments and their peoples to make them scream. The book is an insightful contribution on Africa's contemporary post-colonial liberation politics of development economics. It focuses on Zimbabwe as a synthesis of microcosmic study that provides accessible in-depth analysis of key aspects of sanctions as a weapon of control wielded by the so-called 'powerful' governments of the Global North. Zimbabwe was clobbered with post-independence economic sanctions after its land reform programme, which benefitted its mostly colonially dispossessed African citizens. The land reform was intended as a reversal of colonial injustice and a counter restitutive measure against imperialism. The book invites the reader to see power differently: as compassion and the capacity to right past wrongs by protecting all and sundry from inequality and poverty. Sanctions, even when called targeted, are non-discriminatory as they affect ordinary citizens with the same ferocity and savagery as against intended target, albeit often missing the target. Sanctions are lethal. Sanctions are a graveyard for the poor, weak and vulnerable. This is an idea of power that the Global North failed to grasp when they decided to punish the Mugabe government for daring to contemplate justice and restitution.
Zhero
(2011)
An inspiring and intriguing tale of heroism, Zhero's quest for education and self-worth takes him from the rustic village of Amabra to the cities of Port Harcourt and Lagos. Armed with a determination to succeed against all odds, his quest unearths a malignant problem in the society, which is the degradation and loss of human values. Vincent Egbuson's book is compendium of issues pervading contemporary Nigerian society. It beckons on its readers to emulate acts of kindness and self-sacrifice.
Background The synchrony hypothesis postulates that precise temporal synchronization of different pools of neurons conveys information that is not contained in their firing rates. The synchrony hypothesis had been supported by experimental findings demonstrating that millisecond precise synchrony of neuronal oscillations across well separated brain regions plays an essential role in visual perception and other higher cognitive tasks [1]. Albeit, more evidence is being accumulated in favour of its role as a binding mechanism of distributed neural responses, the physical and anatomical substrate for such a dynamic and precise synchrony, especially zero-lag even in the presence of non-negligible delays, remains unclear. Here we propose a simple network motif that naturally accounts for zero-lag synchronization for a wide range of temporal delays [3]. We demonstrate that zero-lag synchronization between two distant neurons or neural populations can be achieved by relaying the dynamics via a third mediating single neuron or population. Methods We simulated the dynamics of two Hodgkin-Huxley neurons that interact with each other via an intermediate third neuron. The synaptic coupling was mediated through alpha-functions. Individual temporal delays of the arrival of pre-synaptic potentials were modelled by a gamma distribution. The strength of the synchronization and the phase-difference between each individual pairs were derived by cross-correlation of the membrane potentials. Results In the regular spiking regime the two outer neurons consistently synchronize with zero phase lag irrespective of the initial conditions. This robust zero-lag synchronization naturally arises as a consequence of the relay and redistribution of the dynamics performed by the central neuron. This result is independent on whether the coupling is excitatory or inhibitory and can be maintained for arbitrarily long time delays (see Fig. 1). Conclusion We have presented a simple and extremely robust network motif able to account for the isochronous synchronization of distant neural elements in a natural way. As opposed to other possible mechanisms of neural synchronization, neither inhibitory coupling, gap junctions nor precise tuning of morphological parameters are required to obtain zero-lag synchronized neuronal oscillation.
Some requirements for a VERBMOBIL system capable of processing Japanese dialogue input have been explored. Based on a pilot study in the VERBMOBIL domain, dialogues between 2 participants and a professional Japanese interpreter have been analyzed with respect to a very typical and frequent feature: zero pronouns. Zero pronouns in Japanese texts or dialogues as well as overt pronouns in English texts or dialogues are an important element of discourse coherence. As to translation, this difference in the use of pronouns is a case of translation mismatch: information not explicitly expressed in the source language is needed in the target language. (Verb argument positions, normally obligatory in English, are rather frequently omitted in Japanese. Furthermore, verbs in Japanese are not marked with respect to features necessary for pronoun selection in English.)
Zero Point Soldier
(2019)
It took two years for this collection of poems to see the light of day. Two years. Two whole years. But two whole years of thinking, feeling and working through and from one of the strangest and certainly most torturous facts of life on Earth, and one of the least explored themes in the world of the modern woman of Africa, or my world, at least. This is the fact of Death. But not the fact of the death of all. Not the fact of the death of any. It is that of the modern man, the man, of Africa.
The dynamical quantum Zeno effect is studied in the context of von Neumann algebras. It is shown that the Zeno dynamics coincides with the modular dynamics of a localized subalgebra. This relates the modular operator of that subalgebra to the modular operator of the original algebra by a variant of the Kato-Lie-Trotter product formula.