Development to metamorphosis of the nemertean pilidium larva

<p>Abstract</p> <p>Background</p> <p>The nemertean pilidium is one of the most notable planktotrophic larval types among marine invertebrates. The juvenile forms inside the larva from a series of isolated rudiments, called the imaginal discs. The development culminates in catastrophic metamorphosis, in which the larval body is consumed by the juvenile worm. Although the pilidium was first described in 1847, and is commonly found among marine plankton, there is not a single complete description of its development. The few published studies of pilidial development are based on observations of typically unidentified larvae opportunistically collected from plankton at various developmental stages.</p> <p>Results</p> <p>The development of <it>Micrura alaskensis</it>, a common Northwest Pacific coast intertidal nemertean, is described from fertilization to metamorphosis. A staging scheme is proposed based on characteristic developmental milestones. Three pairs of imaginal discs develop as invaginations of larval epidermis. The cephalic discs invaginate from the larval epidermis above the ciliated band, while the cerebral organ discs and the trunk discs invaginate below the ciliated band. All paired imaginal disc invaginations are closely associated with different portions of the larval ciliated band. In addition, two unpaired rudiments contribute to the juvenile - the proboscis rudiment and the dorsal rudiment, which do not develop as invaginations. A pair of thick-walled esophageal pouches previously thought to represent nephridial rudiments give rise to the juvenile foregut. Branched rudiments of protonephridia, and their efferent ducts are also described. Larval and juvenile serotonergic nervous systems are briefly described. Development of the juvenile is completed by 5-8 weeks at 11-15 degrees C. During the rapid metamorphosis the juvenile emerges from and devours the larva.</p> <p>Conclusions</p> <p>This study is the first description of pilidial development from fertilization to metamorphosis in a single species. It is illustrated with photomicrographs of live larvae, diagrams, confocal images, and videos. The findings are discussed in the context of previously published accounts of pilidial development, with which they disagree on several accounts. The results described here indicate a different number, origin and fate of various juvenile rudiments. The proposed staging scheme will be useful in subsequent studies of pilidial development.</p

Orbit decidability, applications and variations

We present the notion of orbit decidability into a more general framework, exploring interesting generalizations and variations of this algorithmic problem. A recent theorem by Bogopolski-Martino-Ventura gave a renovated protagonism to this notion and motivated several interesting algebraic applications

Synthesis and spectroscopic features of iron(II) 1-aryl-5-benzothiazol-2- ylformazanates

New iron(II) coordination compounds with 1-aryl-5-(benzothiazol-2-yl) formazans were prepared. Their compositions and structures were determined by electronic spectroscopy, mass spectrometry, single crystal X-ray diffraction analysis, and magnetochemical measurements. © 2008 Pleiades Publishing, Ltd.Russian Foundation for Basic Researc

Synthesis and catalytic properties of copper(II) 1-aryl-5-benzothiazolylformazanates

New copper(II) benzothiazolylformazane complexes were synthesized and immobilized on AN-18 anion exchanger. The influence of the composition of the coordination core of copper(II) benzthiazolylformazanates and temperature on their catalytic properties in decomposition of H2O2 and oxidation of Na2S in aqueous solution was studied

An Analysis of the Links between Smoking and BMI in Adolescents: A Moving Average Approach to Establishing the Statistical Relationship between Quantitative and Dichotomous Variables

The aim of this study was to determine the effect of smoking on BMI in male adolescents and explore the relationship between smoking status and diet. Methods: A cross-sectional epidemiological study into the health and diet of adolescents was carried out based on a representative sample of 375 vocational school male students aged 16–17 in the city of Chelyabinsk (Russian Federation). The students and their parents filled out verified questionnaires on their socioeconomic status, diet, and smoking status. Students’ height and body weight were measured. A comparative analysis of diets was performed between groups of smokers and non-smokers (149 and 226 individuals, respectively), and the relationship between smoking, body mass index, and actual diet was estimated. The methods used included descriptive statistics, Student’s t-test, Mann–Whitney U test, comparison of proportions, and moving average. Results: Non-smoking adolescent boys tended to have excess body mass compared with smokers (19.0% and 12.1%, respectively). Smokers (adolescent boys) consumed less meat, cereals, beans, and cheeses and more sweet beverages, added sugar, coffee, and alcohol. The bulk of the smokers’ diet was composed of carbohydrates (p = 0.026) and, to a lesser extent, proteins (p = 0.006). Conclusions: Significant differences were discovered in the diet between smokers and non-smokers (among adolescent boys), and smoking was associated with several indicators of unhealthy diet patterns. This is an important conclusion for developing a future program that could additionally protect at-risk groups of adolescents

Prevalence of risk factors of HIV contamination in injection drug using women in the Omsk Region

The results of an epidemiological study of risk factors of HIV infection among women, who inject drugs, are presented in this paper. Incidence of HIV among women during the period from 2005 to 2013 had a significant increasing trend from 2,1 to 63,3 per 100000 women. The predominance of parenteral transmission of HIV, as well as a significant prevalence of substance abuse disorders among women, determined a significant risk of morbidity for women with HIV infection (6,3 per 10,000 women). We included 115 women, taking injection drugs, in our study. Most of the women noted patterns of high risk HIV infection behavior, as well as the lack of knowledge about HIV prevention. 45% of women had been using drugs for 6-11 years, most of them have started using drugs at the age of 16-19 years, 40% of participants have used more than one type of drug, used common needles, syringes, together with other persons, including those with HIV infection. 23,8% of the women mentioned having unprotected sex, including sex with casual sex partners

Uterine microbiome in women with uterine scar defect after cesarean section: Prospective cohort study

Aim. To evaluate the endometrial microbiota in patients with uterine scar defect after cesarean section. Materials and methods. The study included 80 women of reproductive age. The main group included 50 patients with a uterus scar defect due to cesarean section; the comparison group included 30 women with a competent uterus scar due to cesarean section. Patients underwent a Pipelle endometrial biopsy on days 2022 of the menstrual cycle using a double-lumen catheter that excludes sample contamination with vaginal and cervical microflora. A molecular genetic study of the endometrium was performed by real-time polymerase chain reaction using the Femoflor 16 reagent kit (DNA-Technology Moscow). The DNA content in the specimen was measured using software and expressed in genome equivalent (GE) proportional to the number of microorganisms. The statistical data were processed using the Exсel software package and SPSS Statistics 22.0. Results. The study showed the following statistically significant differences: lower count of Lactobacillus spp. 2.600 (1.4303.600) GE/mL vs 3.550 (2.8004.700) GE/mL in patients of the comparison group (p=0.02); higher count of Streptococcus and Staphylococcus spp. 3.270 (3.0003.700) GE/mL and 3.450 (3.2003.600) GE/mL vs 1.030 (0.7601.700) GE/mL and 0.560 (0.1201.200) GE/mL in the comparison group, respectively (p0.00001); higher count of Enterobacteriaceae 2.700 (1.7003.300) GE/mL vs 0.950 (0.6601.120) GE/mL in the comparison group (p0.00001); higher count of Gardnerella/Prevotellabivia/Porphyromonas spp. 2.310 (0.9303.480) GE/mL vs 1.000 (0.0001.860) GE/mL (p=0.003); higher count of Peptostreptococcus spp. 0.195 (0.0001.560) GE/mL vs 0.000 (0.000-0.000) GE/mL (p=0.032); Eubacterium spp. 1.355 (0.1002.460) GE/mL vs 0.000 (0.0001.560) GE/mL (p=0.040). Conclusion. Endometrial dysbiosis in patients with a uterus scar defect after cesarean section due to the possible effects of microorganisms can be considered one of the leading causes of the formation of a uterus scar defect in the postoperative period

STATISTICAL MODELING OF INFLUENCE CIGARETTE SMOKING ON THE STATE OF THE CARDIOVASCULAR SYSTEM OF INDUSTRIAL ENTERPRISES WORKERS

This work explores the impact of cigarette smoking on the state of the cardiovascular system of industrial workers. The registration of intervalograms according to Baevsky R.M. and questioning were used as research methods. The data obtained were subjected to statisti-cal analysis

Body plethysmography in early diagnostics of dust-related respiratory pathology in industrial workers exposed to silicon-containing aerosols

The article dwells upon the usage of body plethysmography techniques and the evaluation of the lungs diffusing capacity in early diagnostics of dust-related respiratory pathology in industrial workers exposed to silicon-containing aero-sols. The purposes of the study were: i) to look at these tools diagnostic perfor-mance with respect to disorders of pulmonary ventilation and gas exchange in siliconaerosols exposed workers; ii) to articulate the indications for body-plethysmographic assessment of the external respiration function. Our team has narrowed on patients with chronic bronchitis and silicosis, and the workers with a high risk of pneumoconiosis. The cases of disorders of pulmonary ventilation and gas exchange have been described. It has been shown that, for a comprehensive study of the external respiration function, patients should be picked-up based on their determined lung diffusing capacity.Статья посвящена применению методов бодиплетизмографии и определения диффузионной способности легких в ранней диагностике пылевой патологии органов дыхания у работников промышленных предприятий, подвергающихся воздействию кремнийсодержащих аэрозолей. Цель работы: показать возможности бодиплетизмографии и диффузионной способности легких в диагностике вентиляционных нарушений и легочного газообмена у работников, подвергающихся воздействию кремнийсодержащих аэрозолей и сформулировать показания для исследования функции внешнего дыхания методом бодиплетизмографии. Внимание сосредоточено на обследовании больных хроническим бронхитом, силикозом и работников группы риска по развитию пневмокониоза. Описаны варианты нарушения вентиляционной функции легких и легочного газообмена. Показано, что отбор пациентов для углубленного исследования функции внешнего дыхания необходимо проводить по диффузионной способности легких