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Herbs used medicinally are a gift from nature to humans, helping to maintain, enhance, and protect our health in important ways. The current study investigates the phytochemical composition, FTIR spectral analysis, and hepatoprotective properties of Distimake dissectus (Jacq.) A.R. Simões & Staples. It is commonly called as ''alamo vine'' belonging to family Convolvulaceae, is a perennial herb, weed and climber native to the United States and distributed across the globe. Traditionally, it is used to snakebite, urinary infection, sprains, cold and scabies chest problems, anti-asthmatic, anti- hyperglycemic, antinociceptive, anti-inflammatory, immunomodulatory, anticarcinogenic. Following a qualitative phytochemical extraction with hexane, chloroform, ethyl acetate and methanol, along with a hot continuous and successive extraction through a Soxhlet extractor. The phytochemical screening indicated the presence of alkaloids, flavonoids, saponins, phenolic compounds, tannins, and glycosides, among other compounds, additionally the quantification of phytochemical content demonstrated the total phenolic content, total flavonoid content, and proanthocyanins content. FT-IR spectroscopic analysis revealed various characteristic peak values with various functional groups hydroxyl group, alkane, nitrile, alkyne, ester, aromatic, alkene groups and etc., The hepatoprotective activity of the methanolic extract was evaluated using the MTT assay, showing concentration-dependent inhibition of cancer cells. The study sheds light on the therapeutic qualities of Distimake dissectus and provides beneficial insights for pharmacology and drug development research. The discovery of hepatoprotective plant-based compounds in these plants may pave the way for the creation of novel therapeutic hepatoprotective agents. [ABSTRACT FROM AUTHOR]

Morphometric measurements of the gut cells of the marine calanoid copepod Acartia tonsa were made over a 24 h diel cycle to test the hypothesis that feeding rhythms in this copepod are limited by the cycles of blishter-like cells (B-cells) in the gut. Copepods were collected from Long Island Sound, New York, USA, in June 1991. Experimental treatments included low (1 μg chlorophyll al) and high (10 μg chlorophyll al) food concentrations. Copepods were fixed and embedded in Epon at six time intervals over the 24 h period, and semi-thin sections through the length of Midgut Zone II were analyzed for gut-cell area and vacuole area, with area measurements integrated to yield estimates of gut-cell volume and vacuole volume. Concurrent measurements of gut fluorescence, a measure of gut fullness, and digestive enzyme activities also were made. A diel cycle in gut fluorescence was observed, most notably in the low-food treatment, which exhibited a 3-fold increase in gut pigments. There was little consistent change in digestive enzyme activities over this time span. Gaps in the gut wall indicative of spent B-cells were observed in 17 of 39 copepods, with no trend over time or food treatment. Generally, only a single gap was seen in any one copepod. B-cells were vacuolated throughout the 24 h period. Morphometric analyses revealed a correlation between gut fluorescence and both maximum vacuole area and vacuole volume, as well as percent vacuolated cell volume, in the low-food treatment. The high-food treatment, which had a relatively smaller increase in gut fluorescence (1.5-fold) during the night cycle, showed no significant increase in vacuole size. B-cells appear to have a life-cycle greater than the diel feeding period, and while B-cell vacuoles respond to the ingested food during the diel cycle, production of B-cells does not appear to be a limiting factor in A. tonsa's feeding cycle. [ABSTRACT FROM AUTHOR]

A comparison of green light emission from both barium- and amorphous boron–based pyrotechnics is described. Emission spectra are shown for both the U.S. Army in-service M125A1 green star cluster formulation and an amorphous boron–potassium nitrate–binder formulation. The main peaks of the emission spectra, average dominant wavelength, and average spectral purity of both formulations are given. The role that combustion products play in determining flame temperature and continuum radiation is also discussed. [ABSTRACT FROM PUBLISHER]

This article summarizes the research activities carried out by the R&D Optical Networks Communications group (COM RD1), at Siemens S.A., in collaboration with both universities and other research institutes. These activities cover various aspects of advanced modulation formats, all optical wavelength conversion, optical quality of signal monitoring in transparent WDM networks, routing, and wavelength assignment in optical networks. [ABSTRACT FROM AUTHOR]

Leprosy is a zoonosis in the southern United States involving humans and wild armadillos. The majority of patients presenting with zoonotic strains of Mycobacterium leprae note extensive outdoor activity but only rarely report any history of direct contact with wild armadillos. Whether M. leprae is transmitted to new vertebrate hosts through the environment independently or with the aid of other organisms, e.g., arthropod vectors, is a fundamental question in leprosy transmission. The objectives of this study were to assess the potential for ticks to transmit M. leprae and to test if viable M. leprae can be maintained in tick-derived cells. To evaluate tick transmission, nymphal Amblyomma maculatum ticks were injected with isolated M. leprae. Infection and transmission were assessed by qPCR. Ticks infected as nymphs harbored M. leprae through vertical transmission events (nymph to adult and adult to progeny); and, horizontal transmission of M. leprae to a vertebrate host was observed. Mycobacterium leprae DNA was detected in multiple tick life cycle stages. Likewise, freshly isolated M. leprae (Thai-53) was used to infect a tick-derived cell line, and enumeration and bacterial viability were assessed at individual time points for up to 49 days. Evaluations of the viability of long-term cultured M. leprae (Thai-53 and Br4923) were also assessed in a mouse model. Tick-derived cells were able to maintain viable M. leprae over the 49-day course of infection and M. leprae remained infectious within tick cells for at least 300 days. The results of this study suggest that ticks themselves might serve as a vector for the transmission of M. leprae and that tick cells are suitable for maintenance of viable M. leprae for an extended period of time. [ABSTRACT FROM AUTHOR]

The earnings difference between white and black workers fell dramatically in the United States in the late 1960s and early 1970s. This article shows that the expansion of the minimum wage played a critical role in this decline. The 1966 Fair Labor Standards Act extended federal minimum wage coverage to agriculture, restaurants, nursing homes, and other services that were previously uncovered and where nearly a third of black workers were employed. We digitize over 1,000 hourly wage distributions from Bureau of Labor Statistics industry wage reports and use CPS microdata to investigate the effects of this reform on wages, employment, and racial inequality. Using a cross-industry difference-in-differences design, we show that earnings rose sharply for workers in the newly covered industries. The impact was nearly twice as large for black workers as for white workers. Within treated industries, the racial gap adjusted for observables fell from 25 log points prereform to 0 afterward. We can rule out significant disemployment effects for black workers. Using a bunching design, we find no aggregate effect of the reform on employment. The 1967 extension of the minimum wage can explain more than 20% of the reduction in the racial earnings and income gap during the civil rights era. Our findings shed new light on the dynamics of labor market inequality in the United States and suggest that minimum wage policy can play a critical role in reducing racial economic disparities. [ABSTRACT FROM AUTHOR]

Aquaculture companies grow the green alga Haematococcus pluvialis (Chlorophyta) to extract the carotenoid astaxanthin to sell, which is used as human and animal dietary supplements. We were requested to identify an unknown pathogen of H. pluvialis from an alga growing facility in the southwestern United States. To identify this zoosporic fungus and determine its phylogenetic placement among other chytrids, we isolated it into pure culture, photographed its morphology and zoospore ultrastructure, and sequenced and analyzed portions of nuc rDNA 18S and 28S genes. The organism belongs in the Chytridiomycota, but a comparison of rDNA with available representatives of the phylum did not convincingly place it in any described order. The unique zoospore ultrastructure supports its indeterminate ordinal position, and the morphology, as determined by light microscopy, did not match any described species. Consequently, we have placed this chytrid in the new genus, Quaeritorhiza, and described it as the new species Q. haematococci in the family Quaeritorhizaceae but otherwise incertae sedis in the Chytridiomycetes. This new taxon is important because it increases the known diversity of Chytridiomycota and the organism has the ability to disrupt agricultural production of an algal monoculture. [ABSTRACT FROM AUTHOR]

Background We present the largest clinicopathologic case series to date of dense deposit disease (DDD) in an Indian population and compare the renal biopsy incidence rate to that seen in a large renal laboratory in USA. Methods Cases of DDD were identified and evaluated from native kidney biopsies reported at Renopath, India and at Arkana Laboratories, in the USA. Renopath receives biopsies from four states, located in the South and Eastern part of India. Arkana Laboratories' biopsies came from 37 states across the USA. Results During the study period, there were a total of 25 patients diagnosed with DDD among the 7335 native kidney biopsies at Renopath. Thus, the biopsy incidence rate (cases of DDD/total renal biopsies/year) is 0.0034. By comparison, there were 10 cases of DDD diagnosed among 26 319 native kidney biopsies at Arkana Laboratories during the same time period, with a renal biopsy incidence rate of 0.00038. Conclusions DDD in this Indian subpopulation has similar clinical and pathologic characteristics when compared to previously reported studies. However, the biopsy incidence rate is about 890% or 8.9 times more common in this subset of the Indian population when compared with a broad cross-section of the US population. In addition to potential genetic factors, environmental conditions and chronic infections likely contribute to the markedly higher biopsy incidence rate. Given the much greater number of patients with DDD in this population, further retrospective and prospective studies would allow more rapid progress in understanding the pathogenesis of DDD and thus potential treatment of patients with DDD. [ABSTRACT FROM AUTHOR]

The article discusses the prevalence of Hand-Arm Vibration Syndrome (HAVS) among industrial workers in the U.S. which caused by hand-transmitted vibration. It highlights the risk of using a hand-held powered tools for prolonged durations that could lead to severe vascular damage with symptoms of cold-induced vasospasms, vibration white finger (VWF) and reduce blood flow. It examines vascular damage through structural and biochemical alterations.

During outbreaks of infectious diseases or in cases of severely ill patients, it is imperative to identify the causative agent. This report describes several events in which virus isolation and identification by electron microscopy were critical to initial recognition of the etiologic agent, which was further analyzed by additional laboratory diagnostic assays. Examples include severe acute respiratory syndrome coronavirus, and Nipah, lymphocytic choriomeningitis, West Nile, Cache Valley, and Heartland viruses. These cases illustrate the importance of the techniques of cell culture and electron microscopy in pathogen identification and recognition of emerging diseases. [ABSTRACT FROM AUTHOR]

Oral tissue engineering aims to treat and fill tissue deficits caused by congenital defects, facial trauma, or malignant lesion surgery, as well as to study the biology of oral mucosa. The Food and Drug Administration (FDA) and the European Medicines Agency (EMA) require a large animal model to evaluate cell-based devices, including tissue-engineered oral mucosa, prior to initiating human clinical studies. Porcine oral mucosa is non-keratinized and resembles that of humans more closely than any other animal in terms of structure and composition; however, there have not been any reports on the reconstruction of a porcine oral mucosa equivalent, probably due to the difficulty to culture porcine fibroblasts. In this study, we demonstrate the feasibility of a 3D porcine oral mucosa equivalent based on a collagen-GAG-chitosan scaffold, as well as reconstructed porcine epithelium by using an amniotic membrane as support, or without any support in form of epithelial cell sheets by using thermoresponsive culture plates. Explants technique was used for the isolation of the porcine fibroblasts and a modified fibroblast medium containing 20% fetal calf serum was used for their culture. The histological and transmission electron microscopic analyses of the resulting porcine oral mucosa models showed the presence of non-keratinized epithelia expressing keratin 13, the major differentiation marker of non-keratinized oral mucosa, in all models, and the presence of newly synthesized collagen fibers in the lamina propria equivalent of the full-thickness model, indicating the functionality of porcine fibroblasts. [ABSTRACT FROM AUTHOR]

Yersinia pestis, the causative agent of plague, has caused several pandemics throughout history and remains endemic in the rodent populations of the western United States. More recently, Y. pestis is one of several bacterial pathogens considered to be a potential agent of bioterrorism. Thus, elucidating potential mechanisms of survival and persistence in the environment would be important in the event of an intentional release of the organism. One such mechanism is entry into the viable but non-culturable (VBNC) state, as has been demonstrated for several other bacterial pathogens. In this study, we showed that Y. pestis became nonculturable by normal laboratory methods after 21 days in a low-temperature tap water microcosm. We further show evidence that, after the loss of culturability, the cells remained viable by using a variety of criteria, including cellular membrane integrity, uptake and incorporation of radiolabeled amino acids, and protection of genomic DNA from DNase I digestion. Additionally, we identified morphological and ultrastructural characteristics of Y. pestis VBNC cells, such as cell rounding and large periplasmic spaces, by electron microscopy, which are consistent with entry into the VBNC state in other bacteria. Finally, we demonstrated resuscitation of a small number of the non-culturable cells. This study provides compelling evidence that Y. pestis persists in a low-temperature tap water microcosm in a viable state yet is unable to be cultured under normal laboratory conditions, which may prove useful in risk assessment and remediation efforts, particularly in the event of an intentional release of this organism. [ABSTRACT FROM AUTHOR]

In this article, the author discusses aspects of the typeface design and copyright protection in the twenty-first century in the U.S. He provides an overview of history of typeface design and a primer on the basic features of typefaces. He presents a survey of the available protection for typeface design under the nation's law. He then determines whether the designs themselves are actually protected or only their embodiment in fonts.

Background: The A/H1N1/2009 influenza pandemic made evident the need for faster and higher-yield methods for the production of influenza vaccines. Platforms based on virus culture in mammalian or insect cells are currently under investigation. Alternatively, expression of fragments of the hemagglutinin (HA) protein in prokaryotic systems can potentially be the most efficacious strategy for the manufacture of large quantities of influenza vaccine in a short period of time. Despite experimental evidence on the immunogenic potential of HA protein constructs expressed in bacteria, it is still generally accepted that glycosylation should be a requirement for vaccine efficacy. Methodology/Principal Findings: We expressed the globular HA receptor binding domain, referred to here as HA63-286- RBD, of the influenza A/H1N1/2009 virus in Escherichia coli using a simple, robust and scalable process. The recombinant protein was refolded and purified from the insoluble fraction of the cellular lysate as a single species. Recombinant HA63-286-RBD appears to be properly folded, as shown by analytical ultracentrifugation and bio-recognition assays. It binds specifically to serum antibodies from influenza A/H1N1/2009 patients and was found to be immunogenic, to be capable of triggering the production of neutralizing antibodies, and to have protective activity in the ferret model. Conclusions/Significance: Projections based on our production/purification data indicate that this strategy could yield up to half a billion doses of vaccine per month in a medium-scale pharmaceutical production facility equipped for bacterial culture. Also, our findings demonstrate that glycosylation is not a mandatory requirement for influenza vaccine efficacy. [ABSTRACT FROM AUTHOR]

Objective: To investigate differences in maturation of germ cells in cryptorchid testes in three different regions. Patients and methods: A total of 103 consecutive patients were operated for unilateral undescended testis in Vojvodina, from March 2006 until September 2007, and had a testicular biopsy performed. Germ cells were counted, and the presence of Ad spermatogonia was noted. Biopsies were compared to biopsies of similar patients from two different regions: Philadelphia, USA (130), and Liestal, Switzerland (55 patients). Results: In Vojvodina, 84.5% of patients had Sertoli cells only, or some spermatogonia, but no Ad spermatogonia, and 15.5% had Ad spermatogonia. In Philadelphia, 59.3% of patients had poor testicular histology, and 40.7% had Ad spermatogonia. In Liestal, 61.8% of patients had no, or some, spermatogonia, but no Ad spermatogonia, and 38.2% had Ad spermatogonia. There was a difference (p = 0.000025) between the patients with normal testicular histology from Philadelphia and those from Vojvodina, as well as between the patients from Vojvodina and Liestal (p = 0.0027). Conclusion: The reduction in the number of germ cells in patients with cryptorchidism from Vojvodina is more pronounced than patients from either Switzerland or USA. This is a unique observation, since such a study has not been published yet. [ABSTRACT FROM AUTHOR]

Despite the extensive and regular use of dental elevators on a daily basis in both general dental and specialist oral and maxillofacial surgical practice, little is known about the history and origins of such instruments and this remains an intriguing question. This question has been the basis for the following article, which gives a brief history of the instruments, discusses their eponymous origins and the history, life and works of the individuals they are named after. In-depth research has also raised other questions about such instruments that could be the focus for further study. [ABSTRACT FROM AUTHOR]

Abstract  The future United States military arsenal is transitioning from homogeneous metallic materials to stronger and lighter heterogeneous composite materials. Although these composites offer numerous advantages such as the ability to tune strength to weight ratios for each particular application, composites are susceptible to numerous damage mechanisms and environmental factors. Accidental in-field impacts resulting from mishandling or transportation loads have been identified by the U.S. Army as the primary cause of damage in composite weapon systems. This paper presents a hybrid approach to detect, locate, and quantify damage in filament wound canisters using a complementary set of vibration-based (transmissibility and embedded sensitivity) and wave propagation-based (phased array beamforming) methods. It is shown that this hybrid approach accurately detects, locates, and quantifies the damage imposed by 1.36 and 6.78 N-m impact energies. By measuring the static stiffness of the baseline canister at the mid-point, it was determined that the 1.36 N-m impact resulted in an overall 6% reduction of the tubes bending stiffness, while the 6.78 N-m impact resulted in a 28% reduction. [ABSTRACT FROM AUTHOR]

A safety characterization specific to children was performed for methyl ethyl ketone (MEK) according to the guidelines of the Voluntary Children's Chemical Evaluation Program (VCCEP). The characterization indicates that MEK exposures are not expected to pose an acute or chronic risk to children. Hazard information, summarized as per the VCCEP Tier structure, indicated no need for additional studies. All exposure pathways potentially relevant to children were considered, including child contact with environmental media, food, drinking water, parental transfer to child (human milk or dermal contact), direct consumer product use, and presence during product use. The assessment found that exposures from anthropogenic sources that children may encounter on a daily basis are very low, and in particular well below the chronic inhalation and oral health benchmarks (RfC and RfD) derived by the U.S. Environmental Protection Agency (USEPA). Indoor uses of consumer products can result in higher acute exposures, but these are short-lived and also fall below chronic benchmarks adjusted to an acute timeframe. In addition, MEK is rapidly metabolized and excreted, thus acute exposures do not lead to an increase in body burden over time. The USEPA concluded the VCCEP submission sufficiently characterized potential risks to children, and that no additional toxicity tests were needed for MEK. [ABSTRACT FROM AUTHOR]

Background. Most West Nile virus (WNV) infections in humans are asymptomatic; severe disease occurs in relatively few patients and typically manifests as encephalitis, meningitis, or acute flaccid paralysis. A few cases of life-threatening disease with diffuse hemorrhagic manifestations have been reported in Africa; however, this clinical presentation has not been documented for any of the 116,700 cases of WNV disease reported in the United States during 1999–2004. We describe a case of fulminant WNV infection in a 59-year-old Florida man who died following a brief illness that resembled hemorrhagic disease caused by Rickettsia reckettsii, dengue virus or yellow fever virus. Methods. Traditional and contemporary diagnostic assays, including culture isolation, electron microscopic examination, reverse-transcriptase polymerase chain reaction amplification, and immunohistochemical stains, were used to confirm systemic WNV infection in the patient. Results. WNV was isolated in a cell culture from a skin biopsy specimen obtained from the patient shortly prior to death. Electron microscopic examination identified the isolate as a flavivirus, and reverse-transcriptase polymerase chain reaction amplified specific WNV sequences from the isolate and patient tissue. Quantitative polymerase chain reaction identified approximately viral copies/mL in the patient's serum. WNV antigens 1 × 107 were detected by immunohistochemical stains in intravascular mononuclear cells and endothelium in skin, lung, liver, kidney, spleen, bone marrow, and central nervous system; no viral antigens were identified in neurons or glial cells of the central nervous system. Conclusions. Although hemorrhagic disease is a rare manifestation of WNV infection, the findings provided by this report may offer new insights regarding the clinical spectrum and pathogenesis of WNV disease in humans. [ABSTRACT FROM AUTHOR]

Ticks, including many that bite humans, are hosts to several obligate intracellular bacteria in the spotted fever group (SFG) of the genus Rickettsia. Only Rickettsia rickettsii, the agent of Rocky Mountain spotted fever, has been definitively associated with disease in humans in the United States. Herein we describe disease in a human caused by Rickettsia parkeri, an SFG rickettsia first identified >60 years ago in Gulf Coast ticks (Amblyomma maculatum) collected from the southern United States. Confirmation of the infection was accomplished using serological testing, immunohistochemical staining, cell culture isolation, and molecular methods. Application of specific laboratory assays to clinical specimens obtained from patients with febrile, eschar-associated illnesses following a tick bite may identify additional cases of R. parkeri rickettsiosis and possibly other novel SFG rickettsioses in the United States. [ABSTRACT FROM AUTHOR]

During May and June 2003, the first cluster of human monkeypox cases in the United States was reported. Most patients with this febrile vesicular rash illness presumably acquired the infection from prairie dogs. Monkeypox virus was demonstrated by using polymerase chain reaction in two prairie dogs in which pathologic studies showed necrotizing bronchopneumonia, conjunctivitis, and tongue ulceration. Immunohistochemical assays for orthopoxviruses demonstrated abundant viral antigens in surface epithelial cells of lesions in conjunctivae and tongue, with lower amounts in adjacent macrophages, fibroblasts, and connective tissues. Viral antigens in the lung were abundant in bronchial epithelial cells, macrophages, and fibroblasts. Virus isolation and electron microscopy demonstrated active viral replication in lungs and tongue. These findings indicate that both respiratory and direct mucocutaneous exposures are potentially important routes of transmission of monkeypox virus between rodents and to humans. Prairie dogs offer insights into transmission, pathogenesis, and new vaccine and treatment trials because they are susceptible to severe monkeypox infection. [ABSTRACT FROM AUTHOR]

Presents a study that examined the reciprocal influence of the actors on Internal Revenue Service (IRS) audits, taxpayer litigations and court verdicts in the U.S. Analysis of the efficiency of IRS policies; Assessment of the equity in the U.S. Supreme Court; Details on the institutional control in the IRS.

Examines the effect of the presence of Cryptobia branchialis flagellate on tilapia at the Salton Sea, California. Negative direct effect of c. branchialis on the epithelial cells of fish gills; Reduction of the respiratory lamellae in infected fish; Presence of copius mucus on the gill surface.

Presents several abstracts in the 32nd Annual Meeting of the American College of Veterinary Ophthalmologists in Sarasota, Florida. 'Feline Neuro-Retinal Transplantation Procedures,' by Kristina Narfström and Ragnheidur Bragadottir; 'Primary Glaucoma in Burmese Cats,' by E.C.G.M. Hampson, R.I.E. Smith and M.E. Bernays.

This project sought to identify characteristics and lasting contributions of 19th-century members of the American Neurological Association (ANA). Members were categorized by elite status, citation frequency, founder or charter member, elected to honorary membership, published a monograph on a neurologic or psychiatric topic, born in the United States or Canada, and received any medical training outside the United States or Canada. Citations to 19th-century publications in Science Citation Index were analyzed for the period 1974-1995. ANA membership was restrictive, but membership nevertheless increased dramatically in the first 25 years from its founding in 1875. 19th-century ANA members frequently served in a leadership capacity within the organization, published neurologic or psychiatric monographs, and received medical training abroad. Highly cited members were more likely to be instrumental in founding and developing the organization, and were likely to be recognized by their contemporaries as eminent. 19th-century ANA members made significant and lasting contributions in many areas of neurology and psychiatry. Articles with lasting relevance were early descriptions, points of comparison, and controversial articles. [ABSTRACT FROM AUTHOR]

SUMMARYThe development and release of the unique vegetative propagules of the freshwater encrusting alga Hildenbrandia angolensis Welwitsch ex West et West, gemmae, were studied using several different microscopic and histochemical techniques. In addition, the seasonality of gemma production was monitored bimonthly over a 12-month period in two spring-fed streams in Texas, USA. Gemmae differentiate within the thallus and are subsequently released from the surface of the crust. Release of the gemmae most likely occurs by digestion of surrounding cells, as suggested by the presence of starch granules and lipid globules in the region between the released gemma and the thallus. The initial separation of the gemmae from the thallus occurs from the sides of the gemma or the bottom, or possibly simultaneously. Contrary to previous studies, we have observed that gemma production occurs endogenously within the thallus of freshwater Hildenbrandia, rather than on the surface of the crust in raised structures. Histochemical tests and electron microscopic examination indicate that the cells of the gemmae contain a large amount of floridean starch. The starch granules frequently form rings surrounding the nuclei of both gemma and thallus cells; a feature infrequently reported for florideophyte red algae. Our seasonality investigations indicate that large fluctuations in gemma production occur over 1 year, but at least some gemma production continues year-round in the streams examined. [ABSTRACT FROM AUTHOR]

Reports on the eukaryotic community of the Santa Barbara Basin in California. Support of an abundant protistan and metazoan meiofaunal community; The presence of prokaryotic symbionts; and microaerophile and anaerobic taxa; Opportunities for the testing of symbiosis hypotheses of eukaryogensis.

Ultrastructural features of oogenesis were examined in the pelagic polychaetes Rhynchonerella angelini and Alciopa reynaudii which were collected from Bahamian waters by a manned submersible during 1979 and 1980. No definitive ovary was detected in either species. Oogonia are released into the coelom as packets of cells, where they undergo mitotic division while surrounded by an envelope of sheath cells. Cytokinesis is incomplete, resulting in intercellular bridges between oogonia. Oocytes undergo early stages of meiosis characterized by the presence of synapsed chromosomes, followed by a period of rapid cytoplasmic and nuclear growth. Oocytes are released from the packets in the early vitellogenic phase into the coelom, where they undergo yolk synthesis as solitary coelomic cells. Vitellogenesis includes both autosynthetic and heterosynthetic processes. Autosynthesis involves the fusion of secretory vesicles formed by the combined activity of the rough endoplasmic reticulum and Golgi complex, with convoluted electron-dense tubular bodies of unknown origin. Heterosynthesis involves the intense uptake of exogenous precursors through endocytosis and their fusion into nascent yolk bodies which, in turn, are presumed to fuse with autosynthetically-derived yolk bodies. No nutrient stores were detected in somatic tissues. Early and middle stages of vitellogenic oocytes were absent from the coelom. This absence combined with the high level of endocytotic activity suggests that vitellogenesis occurs rapidly. These features, in combination with the presence of an exceptionally thin body wall and gut, might serve as related adaptations for predator avoidance by the maintenance of relatively low tissue-density. Alciopid, phyllodocid, and nereid polychaetes share some common reproductive features including the presence of 'dispersed' ovaries, clusters of syncytial germ cells which undergo meiosis while enveloped by somatic cells and the release of oocytes from the clusters prior to vitellogenesis. [ABSTRACT FROM AUTHOR]

Sulfur content and fine structure were studied for tissues of three species of clams, Lucinoma annulata, Calyptogena elongata and Lucina floridana, which inhabit sulfide-rich environments and whose gills harbor symbiotic sulfur bacteria. Lucinoma annulata and C. elongata were dredged from the Santa Barbara basin, California, USA, at a depth of 480 to 490 m, and Lucina floridana were dug from below the roots of seagrasses in Saint Joseph Bay, Florida, at a depth of 0.25 to 2m. Foot tissue of Lucinoma annulata, without symbionts, had a total sulfur content of 1.4±0.1 (SD) mg 100 mg dry weight of tissue (%DW). The symbiont-containing gill tissue of different individuals of L. annulata varied in color from dark red to pale yellow, and the total sulfur content was 2.5±0.4% DW in red gills and was 5.6±3.3 % DW in the yellowest gills. Maintenance of L. annulata in the laboratory for 21 d in the absence of sulfide resulted in the loss from the gill of yellow deposits which were elemental sulfur in the form of liquid-crystalline sulfur globules rather than solid orthorhombic sulfur crystals. The foot tissue did not contain elemental sulfur. When examined by freeze-etch microscopy, sulfur globules were found only within bacteria and not in the animal host cytoplasm. Sulfur globules were confined to the periplasmic space of the bacteria. C. elongata and Lucina floridana resembled Lucinoma annulata in the physical form and distribution of elemental sulfur. The absence of elemental sulfur in the animal cytoplasm suggests that its formation from sulfide is not a detoxification scheme to protect animal tissue from sulfide toxicity. The sulfur deposits probably represent inorganic energy reserves that permit the symbiotic bacteria to function even during the temporary absence of external sulfide. [ABSTRACT FROM AUTHOR]

Resting cells of Melosira granulata (Ehr. ) Ralfs were collected from the anoxic sediments of Douglas Lake, Michigan. Sediment containing M. granulatas was inoculated into distilled water and incubated into distilled water and incubated in a growth chamber for one week during which observations were made on the cytological differentiation process. Cells classified as "condensed," i.e. containing a dark brown cytoplasmic mass were identified as resting cells. The differentiation process consisted of a seris of gradual cytological changes that included elongation of the cytoplasmic mass and recognition of definable organelles to the point where the cells were non-distinguishable from water column vegetative cells. Differentaiating cells accumulated large polyphosphate and lipid granules. However, these granules disappeared just prior to cell division. The complete differentiation or rejuvenation sequence occurred in some cells in less than 24 h. However, not all dormant cells rejuvenated at the same time and it was observed that the lag period for rejuvenation increased with resting cell age (depth of burial in sediments). In the [sup14]C uptake studies, label was initially observed in condensed state cells. The label gradually progressed to the more differentiated forms. Total carbon uptake during the rejuvenation process was initially lower in the rejuvenating cells, but roughly equal to water column populations after 8 h, indicating a period of high metabolic activity in the rejuvenating cells between 1 and 8 h. [ABSTRACT FROM AUTHOR]

Rhamnocharysis aestuarinae from Ipswich, Massachusetts, is a new species of benthic marine chrysophyta. Details are given describing its gross and fine structure morphology, its reproductive life history as understood from both field and culture studies, and its ecology and probable systematic position in the Chrysomeridaceae (Sarcinochrysidales). [ABSTRACT FROM AUTHOR]

The article focuses on the introduction of nylon, invented by Wallace Carothers, by E. I. du Pont de Nemours & Co. to the U.S. market. During the annual "Herald Tribune" forum, Charles M. A. Stine, director of research and development of Du Pont, introduced nylon to the public and explained that nylon was derived from coal, air, and water to form into filaments. In 1936, Du Pont Rayon Co. vice president B. M. May negotiated with president L. A. Yerkes to come up an official name for nylon or sometimes referred as Rayon #66. D. A. Kelsey of Trade Mark division suggested that the invention should be given a generic name rather than a trade name because the establishment of suitable generic name is necessary for a patented product before the application of a valid trade mark.

This article will examine the Supreme Court's evaluation of the constitutional validity of Montana's coal severance tax. In addition, the article will explore the policy implications of such a severance tax for other energyproducing states. Finally, the article will evaluate which branch of government, Congress or the courts, should have the power to control such severance taxes, and how that power should be exercised. [ABSTRACT FROM AUTHOR]

This article focuses on abstracts of papers presented at the 32nd annual meeting of the American Society of Dermatopathology at Intercontinental Hotel, New Orleans between February 1-3, 1995. The Kveim-Siltzbach Reactions (KSR) is an important model for investigating immunologic events in granuloma formation. It has been shown that T lymphocyte predominance with oligocionality of infiltrating cells in 4 week-old KSR. Verruciform xanthoma is a rare benign condition that commonly involves the oral mucosa. Cutaneous lesions are less often observed, predominantly occurring at anogenital sites. Despite anecdotal reports of its occurrence in a variety of disease states, the etiology of this condition remains unclear.

A 34-year-old African patient with AIDS developed a new form of oral leucoplakia closely resembling the "hairy" leucoplakia described by Greenspan in male homosexuals in the San Francisco area. A herpes-like virus was seen on ultrastructural analysis with electron microscopy. This case supplies further evidence suggesting that the syndrome in patients originating in Central Africa is similar to the acquired immunodeficiency syndrome (AIDS) reported in American patients. [ABSTRACT FROM AUTHOR]