Cell proliferation and differentiation kinetics during spermatogenesis in Hydra carnea

Spermatogenesis inHydra carnea was investigated. The cell proliferation and differentiation kinetics of intermediates in the spermatogenesis pathway were determined, using quantitative determinations of cell abundance, pulse and continuous labelling with3H-thymidine and nuclear DNA measurements. Testes develop in the ectoderm of male hydra as a result of interstitial cell proliferation. Gonial stem cells and proliferating spermatogonia have cell cycles of 28 h and 22 h, respectively. Stem cells undergo four, five or six cell divisions prior to meiosis which includes a premeiotic S+G2 phase of 20 h followed by a long meiotic prophase (22 h). Spermatid differentiation requires 12–29 h. When they first appear, testes contain only proliferating spermatogonia; meiotic and postmeiotic cells appear after 2 and 3 days, respectively and release of mature sperm begins after 4 days. Mature testes produce about 27,000 sperm per day over a period of 4–6 days: about 220 gonial stem cells per testis are required to support this level of sperm differentiation. Further results indicate that somatic (e.g. nematocyte) differentiation does not occur in testes although it continues normally in ectodermal tissue outside testes. Our results support the hypothesis that spermatogenesis is controlled locally in regions of the ectoderm where testes develop

Degradation of anthracene: Influence of adsorbents from inorganic activation

The use of rice and melon husks in their raw, carbonized (at 400°C and 600°C) and activated (using 10%, v/v orthophosphoric acid) form to catalyze the degradation of anthracene in sandy soil was investigated. Rice husk carbonized at 600°C and activated was found to be a better adsorbent than melon husk under same condition. After five weeks of degradation experiment the anthracene reduced from an initial concentration of 5000 to 1009.7 and 1200.2 μg/g soil for rice and melon husks, respectively, while the control reduced to 2671.0 μg/g soil. Result of the batch degradation process of anthracene was found to follow first order heterogeneous kinetics with rice husk carbonized at 600°C and activated having the fastest reaction rate constant of 0.0018 h-1 followed by melon husk with 0.0016 h-1 while the control had 0.0009 h-1.The regression coefficients obtained from the analysis of the experimental data used to test the order of reaction were greater than 88% showing a good reliability of the data obtained.Keywords: Degradation, polycyclic aromatic hydrocarbon, anthracene, rice husk, melon hus

Influence of base and photoacid generator on deprotection blur in extreme ultraviolet photoresists and some thoughts on shot noise

A contact-hole deprotection blur metric has been used to monitor the deprotection blur of an experimental open platform resist (EH27) as the wt % of base and photoacid generator (PAG) were varied. A six times increase in base wt % is shown to reduce the size of successfully patterned 1:1 line-space features from 52 to 39 nm without changing deprotection blur. Corresponding isolated line edge roughness is reduced from 6.9 to 4.1 nm. A two times increase in PAG wt % is shown to improve 1:1 line-space patterning from 47 to 40 nm without changing deprotection blur or isolated line edge roughness. A discussion of improved patterning performance as related to shot noise and deprotection blur concludes with a speculation that the spatial distribution of PAG molecules has been playing some role, perhaps a dominant one, in determining the uniformity of photogenerated acids in the resists that have been studied. © 2008 American Vacuum Society

Mortality among Diabetes In-Patients in Port-Harcourt, Nigeria

Background: Diabetes mellitus is a major cause of mortality and morbidity among in-patients in Nigeria. It may result from the acute metabolic complications or from the inexorable effects of chronic complications in the major organ systems. Objectives: This study was to determine the death rates and causes of death among in-patients with diabetes at an urban tertiary hospital in Port-Harcourt. Materials and Methods: The medical records of patients admitted with diabetes mellitus into the medical wards of the University of Port Harcourt Teaching Hospital from 1995-2004 were reviewed. The sources of data were the ward admission, death registers, death certificates and medical records. The annual and overall fatality rates were calculated from the available data. Results: During the period under review, 6,574 patients were admitted into the medical wards. Out of these, 686 (10.4%) were due to diabetes and its complications. The diabetic patients comprised of 428 (62.4%) males and 258 (37.6%) females giving a M:F ratio of 1.7:1. One hundred and eighteen of the diabetic patients died giving a case fatality of 17.2%. The main causes of death were diabetic ketoacidosis (DKA) (21.2%), diabetic mellitus foot syndrome (DMFS) (19.5%) and renal failure (12.7%). Diabetic emergencies accounted for 39.8% of all deaths. Conclusion: Diabetes mellitus is a significant cause of medical admissions in Port-Harcourt. The case mortality is very high especially from acute metabolic causes. There is a need for improved management of diabetes in Nigeria. Keywords: Mortality, Diabetes in-patients, Niger Delta

KAJIAN SUB SEKTOR EKONOMI POTENSIAL DALAM MENDUKUNG FUNGSI KOTA CILEGON

Penelitian ini diarahkan untuk menilai sektor potensial dalam mendukung fungsi kota terdapat tiga kriteria yang ditetapkan yakni meliputi peranan struktur ekonomi, basis ekonomi, perubahan struktur ekonomi yang dilihat dengan menggunakan variabel PDRB Kota Cilegon. Kriteria tersebut terdiri masing-masing dua sub kriteria, yakni kriteria peran struktur ekonomi terdiri dari kontribusi PDRB dan laju pertumbuhan PDRB, basis ekonomi terdiri dari peranan suatu sektor dan penggandaan suatu sektor kegiatan, perubahan struktur ekonomi terdiri dari perubahan pertumbuhan sektor ekonomi dan perubahan aktivitas sektor ekonomi. Metodologi penelitian yang di gunakan adalah menggunakan pendekatan deskriptif. Metoda analisis yang di gunakan adalah menggunakan analisis struktur ekonomi, loqation question, shift share, AHP (analysis hirarcical process) dan analisis indeks gabungan komponen petensial ekonomi & fungsi kota. Hasil penelitian menunjukkan sub sektor potensial yang terdapat pada Kota Cilegon diantaranya adalah sub sektor penggalian, industri tanpa migas, listrik, perdagangan besar dan eceran, angkutan laut, angkutan sungai dan penyeberangan, bank, lembaga keuangan lainnya dan jasa perusahaan. Diantara kesembilan sub sektor potensial yang terdapat pada Kota Cilegon, sub sektor yang dapat mendukung fungsi Kota Cilegon adalah sub sektor industri tanpa migas, sedangkan fungsi lainnya masih belum dapat mendukung fungsi yang diemban Kota Cilegon baik dari segi spasial maupun non spasial.&nbsp

A systematic review reveals conflicting evidence for the prevalence of antibodies against the sialic acid ‘xenoautoantigen’ Neu5Gc in humans and the need for a standardised approach to quantification

Copyright \ua9 2024 Hutton, Scott, Robson, Signoret and Fascione.Despite an array of hypothesised implications for health, disease, and therapeutic development, antibodies against the non-human sialic acid N-glycolylneuraminic acid (Neu5Gc) remain a subject of much debate. This systematic review of 114 publications aimed to generate a comprehensive overview of published studies in this field, addressing both the reported prevalence of anti-Neu5Gc antibodies in the human population and whether experimental variation accounts for the conflicting reports about the extent of this response. Absolute titres of anti-Neu5Gc antibodies, the reported prevalence of these antibodies, and the individual variation observed within experiments were analysed and grouped according to biological context (‘inflammation’, ‘xenotransplantation’, ‘biotherapeutic use’, ‘cancer’, and ‘healthy populations’), detection method, target epitope selection, and choice of blocking agent. These analyses revealed that the experimental method had a notable impact on both the reported prevalence and absolute titres of anti-Neu5Gc antibodies in the general population, thereby limiting the ability to ascribe reported trends to genuine biological differences or the consequence of experimental design. Overall, this review highlights important knowledge gaps in the study of antibodies against this important xenoautoantigen and the need to establish a standardised method for their quantification if the extent of the importance of Neu5Gc in human health is to be fully understood

Non-Preemptive Scheduling on Machines with Setup Times

Consider the problem in which n jobs that are classified into k types are to be scheduled on m identical machines without preemption. A machine requires a proper setup taking s time units before processing jobs of a given type. The objective is to minimize the makespan of the resulting schedule. We design and analyze an approximation algorithm that runs in time polynomial in n, m and k and computes a solution with an approximation factor that can be made arbitrarily close to 3/2.Comment: A conference version of this paper has been accepted for publication in the proceedings of the 14th Algorithms and Data Structures Symposium (WADS

Examining Emotion Perception Agreement in Live Music Performance

Current music emotion recognition (MER) systems rely on emotion data averaged across listeners and over time to infer the emotion expressed by a musical piece, often neglecting time- and listener-dependent factors. These limitations can restrict the efficacy of MER systems and cause misjudgements. In a live music concert setting, fifteen audience members annotated perceived emotion in valence-arousal space over time using a mobile application. Analyses of inter-rater reliability yielded widely varying levels of agreement in the perceived emotions. A follow-up lab study to uncover the reasons for such variability was conducted, where twenty-one listeners annotated their perceived emotions through a recording of the original performance and offered open-ended explanations. Thematic analysis reveals many salient features and interpretations that can describe the cognitive processes. Some of the results confirm known findings of music perception and MER studies. Novel findings highlight the importance of less frequently discussed musical attributes, such as musical structure, performer expression, and stage setting, as perceived across different modalities. Musicians are found to attribute emotion change to musical harmony, structure, and performance technique more than non-musicians. We suggest that listener-informed musical features can benefit MER in addressing emotional perception variability by providing reasons for listener similarities and idiosyncrasies

How can we reduce the risk of mother-to-child transmission of HIV during invasive obstetric procedures?

Antenatal invasive obstetric procedures may be diagnostic or therapeutic, and are performed at different stages of pregnancy for various indications. The most common indication for an invasive procedure during pregnancy is for fetal karyotyping when a chromosomal abnormality or a genetic defect is suspected, either from the couple’s history or from ultrasound assessment of the fetus. Other less common but equally important indications may be diagnostic (fetoscopy, fetal tissue sampling, estimation of fetal haemoglobin) or therapeutic (aspiration of various fetal cavities, fetal blood transfusion and embryo reductions). In a high HIV prevalence setting like South Africa, a significant proportion of pregnant women in need of invasive procedures will be HIV-infected