Viviparous development in the Antarctic sponge Stylocordyla borealis Loven, 1868

The complete larval development of the deep-sea sponge Stylocordyla borealis (from eggs to young sponges) was followed in sponges from the Antarctic waters of Terra Nova Bay. S. borealis shows a viviparous strategy which leads to young complete sponges incubated in the mother body, with cortex, spicules and choanocyte chambers. This development can be considered a K-strategy, which is usually employed by deep-sea organisms and cold-water benthic invertebrates.     

Prevalence,Characteristics, and Correlates of Teasing Experiences among Overweight Children vs. Non‐overweight Peers

Objective: Information regarding the prevalence, nature, sources, and psychosocial correlates of teasing was obtained for overweight (OV) children (10 to 14 years of age) vs. non‐overweight (non‐OV) peers. It was hypothesized that weight‐related teasing would be negatively correlated with self‐esteem in specific domains and with enjoyment of physical/social activities and positively correlated with loneliness, bulimic behaviors, body dissatisfaction, and enjoyment of sedentary/isolative activities. Research Methods and Procedures: Teasing experiences and psychosocial correlates were assessed among OV children from a fitness camp and a demographically similar school sample of non‐OV children. Results: Among the OV children, appearance‐related teasing was more prevalent, frequent, and upsetting, involved disparaging nicknames focusing more on weight rather than less stigmatized aspects of appearance, and more often perpetrated by peers in general rather than a specific peer. Degree of teasing within the full sample was significantly associated with higher weight concerns, more loneliness, poorer self‐perception of one's physical appearance, higher preference for sedentary/isolative activities, and lower preference for active/social activities, all but the latter association holding up above and beyond actual weight status and demographics. Among OV children, teasing was associated with bulimic behaviors. Associations with type of teasing showed specificity, with weight‐related teasing predicting weight and appearance variables and competency‐related teasing related to social domain factors. Discussion: When frequency, intensity, emotional impact, and stigmatized content are examined, findings indicate that teasing is more severe for OV children. Effective interventions are needed to help victims cope with and prevent further weight‐related teasing, which may improve peer functioning, enhance weight control efforts, and reduce risk for future eating disturbance.     

Protein Kinase Activities Associated with Actin Cytoskeleton in Xenopus laevis Oocytes and Eggs

Protein phosphorylation with specific protein kinases plays the key role in the regulation of meiotic maturation of oocytes. However, little is known about the contribution of kinases to the temporal and positional regulation of the cytoskeleton rearrangement in maturing oocytes, including the actin cytoskeleton. In order to study a relationship between the kinase activities and actin cytoskeleton rearrangement, we analyzed protein phosphorylation in the isolated actin cytoskeleton of Xenopus laevis oocytes. Analysis of the full grown oocytes and eggs injected with [-³²P]ATP has revealed phosphorylation of many proteins associated with the actin cytoskeleton and shown the appearance of three additional major phosphoproteins, 20, 43, and 69 kDa, during oocyte maturation. A significant number of these phosphoproteins were also found after incubation of the isolated cytoskeleton with [-³²P]ATP in vitro, thus confirming that the kinases modifying these substrates are also specifically associated with actin. The in vivo and in vitro kinase activities were also stimulated during maturation. Analysis of kinase self-phosphorylation in situ and protein phosphorylation in solutions and substrate containing gels revealed a set of actin-associated kinases, including cAMP- and Ca²⁺-dependent kinases, as well as MAP, p34^cdc2, and tyrosine kinase activities. Their level was the highest in the eggs. The involvement of kinases in the actin cytoskeleton rearrangement during oocyte maturation is discussed.     

Epistemology of living organisms in Aristotle’s philosophy

Summary For Aristotle, living entities are exemplars of substance being. This means that they show a unity of matter and form on the one hand and of potency and act on the other, in contrast to the duality shown in these respects by accidental beings, exemplified by artefacts. An animal, although composed of the same elements (arche) considered by presocratic philosophers, is defined as an individual unity, generated and maintained by an organisation which relates its parts in a hierarchical and functional way. Crucial to his understanding of the living is the hierarchy in which each part is defined by fitness to a function, as an instrument (organon), performing within the whole. The whole being is also an instrument (an organism) for a specific kind of life, which actualises an internal and specific principle (psuche). Both the regularity of appearance of each organism and its fitness to a specific function justify the introduction, in addition to the study of necessary causes, of an additional way of analysis in terms of hypothetical necessities, or necessary conditions for a goal to be attained. Fitness to a function and regularity of appearance make necessary the analysis not just of the elementary components, but of another principle (eidos, form) which defines a structure directed to a goal. While for accidental beings matter can survive their destruction, the corruption (pthora) of living entities causes the disruption of the entire unity of matter and form. Living entities, both as matter and form, show therefore a temporal limitation in being generated and corrupted, although they persist as specific forms since they generate offspring which regularly share their differential characteristics defined in their form. After reviewing recent interpretations of Aristotle’s biological writings, I will suggest the usefulness of this conceptual framework to analyse some problems approached by current developmental biology.     

Cognitive Change in Obese Adolescents Losing Weight

Objectives: To investigate how obese adolescents think about themselves in terms of exercise, eating, and appearance and whether these cognitions change over the course of a residential weight loss camp. Research Methods and Procedures: Obese adolescents [N = 61; age, 14.1 (±0.2) years; BMI, 33.9 (±0.7) kg/m²] completed assessments of body weight and height and self‐esteem and a sentence‐completion test eliciting thoughts and beliefs about exercise, eating, and appearance at the start and end of the camp (mean stay, 26 days). They were compared with a single assessment of 20 normal‐weight adolescents [age, 15.4 (±0.2) years; BMI, 21.8 (±0.5) kg/m²]. Results: The obese adolescents lost 5.7 kg and reduced their BMI SD score by 0.25. Camp residence was associated with a significant reduction in the number of negative automatic thoughts and an increase in positive thoughts, especially related to exercise and appearance. There was no change in conditional beliefs, either functional or dysfunctional. Including BMI SD score change as a covariate took away all the main and interaction effects of time, showing that cognitive change was largely accounted for by the reduction in weight. Despite this improvement, campers remained cognitively more negative and dysfunctional than the normal‐weight comparison adolescents. Discussion: Obese adolescents not only lost weight, but they improved their self‐representation, specifically in terms of automatic thoughts about exercise and appearance. Although these are short‐term cognitive changes, they reflect positively on the camp experience and show the value of psychological improvement in assessing obesity‐treatment outcomes.     

Plant strategies along mountain vegetation gradients: a test of two theories

Abstract. We test the predictions of two theories on plant strategies along vegetation gradients of a North Scandinavian mountain area, from herb-rich birch forests at 250 m. a.s.l. to the summit at 1530 m. a.s.l. According to Grime's theory, stressful physical conditions select for an adaptational syndrome called S-strategy. The theory predicts that the prevalence of S-strategic features increases monotonically from forests to high-alpine boulder fields. Alternatively, the traits that Grime regards as S-strategic can be interpreted as adaptations to high natural-grazing pressure which culminates in moderately stressful habitats: productive enough to sustain grazers but yet so barren that moderate grazer densities suffice to deplete the vegetation. The observed vegetation patterns support this alternative view. We thus suggest that Grime's triangle should be revised as to make the role of grazing as the central causal factor behind the third strategy explicit.     

The evolutionary history of Drosophila buzzatii

Introgression of a chromosome segment from Drosophila serido into the genome of its sibling D. buzzatii brought about the release of mutator potential in the hybrids. Mutator activity was determined by examining the frequency of new chromosomal rearrangements, that appeared only in the progeny of hybrid individuals. Mutation frequency was 30 times greater in the progeny of hybrid males than in that of hybrid females. There was a remarkable influence of the D. buzzatii genetic background on the frequency of production of these new rearrangements. The appearance of a new rearrangement did not depend on the genotype of the larva that bore it, but only on that of its hybrid progenitor. Among the new rearrangements there were inversions, translocations, and duplications. The number of translocations was significantly lower than that of inversions or duplications; this last type was the most frequently recorded. The distribution of the aberrations among the four major autosomes seemed to be homogeneous, although the total number of breakpoints was significantly greater in chromosome 4 than in the others. No rearrangement was found on the X chromosome. Breakpoints within three of the four affected autosomes were not randomly distributed.     

不同品种(系)榛子坚果表型性状差异性分析及其综合评价

该研究以目前主栽的平榛、毛榛及25个平欧杂种榛品种(系)的坚果为研究对象,测定了不同品种(系)榛子坚果的17个表型性状指标,用方差分析、相关性分析、聚类分析和主成分分析方法对其进行差异性分析和综合评价,为国内榛树品种(系)的选优、开发及加工利用提供科学依据。结果表明：(1)不同品种(系)榛子坚果的17个表型性状指标存在显著差异,其中果壳质量、坚果体积和坚果质量差异最为明显,变异系数分别为31.49%、30.44%、27.50%,横纵径比、果形指数、伸长率、圆球度的变异系数均小于10%。(2)平欧杂种榛坚果的纵径、横径、侧径及坚果质量、果仁质量、出仁率等指标显著优于毛榛和平榛,其中杂种榛的平均果仁质量(0.70～1.46 g)和出仁率(31.48%～56.12%)显著高于平榛(0.51 g、35.13%)和毛榛(0.37 g、38.12%)。(3)榛子坚果表型性状指标间的相关性分析表明,榛子坚果体积越大,其质量和果仁质量也越大,果壳越薄则出仁率更高。(4)主成分分析结果发现,影响榛子坚果综合得分的主要指标为坚果的纵径、横径、侧径、质量和果仁质量,其次是果形指数、横纵径比、出仁率、果仁饱满...     

Improved thermal stability and activity in the cold-adapted lipase B from Candida antarctica following chemical modification with oxidized polysaccharides

In order to improve the thermal stability (t_1/2) and activity of lipase B from cold-adapted Candida antarctica (CALB), amino groups of the enzyme were chemically linked to a range of oxidized polysaccharides using a range of reducing agents. By chemically modifying CALB using 0.1% dextran (250 kDa) at pH 8.6 for 10 days using borane–pyridine complex as reducing agent, increased thermal stability (t_1/2, 168 min at 70°C) and activity (65% higher specific activity) was achieved compared to the unmodified enzyme (t_1/2, 18 min at 70°C). Improvements in thermostability were generally better with high molecular weight polymers such as dextran (40 and 250 kDa) or ficoll (70 and 400 kDa) in comparison to low molecular weight inulin (5 kDa). The shape of the polymer also appeared to be important with elongated, elipsoidal-shaped dextran providing better thermostabilization than spherical-shaped ficoll. Borane–pyridine complex was found to be a good, non-toxic reducing agent for improving thermostability, compared with sodium borohydride and sodium cyanoborohydride. An interesting finding was that, in all cases, specific activity of the modified enzymes increased with a concomitant increase in thermostability. This response defies the general principle of a trade-off between activity and stability, and demonstrates that chemical modification provides new avenues for improving the thermal stability of enzymes from psychrophiles without sacrificing their activity.     

Reconstruction of ancestral karyotype illuminates chromosome evolution in the genus Cucumis

Karyotype dynamics driven by complex chromosome rearrangements constitute a fundamental issue in evolutionary genetics. The evolutionary events underlying karyotype diversity within plant genera, however, have rarely been reconstructed from a computed ancestral progenitor. Here, we developed a method to rapidly and accurately represent extant karyotypes with the genus, Cucumis, using highly customizable comparative oligo-painting (COP) allowing visualization of fine-scale genome structures of eight Cucumis species from both African-origin and Asian-origin clades. Based on COP data, an evolutionary framework containing a genus-level ancestral karyotype was reconstructed, allowing elucidation of the evolutionary events that account for the origin of these diverse genomes within Cucumis. Our results characterize the cryptic rearrangement hotspots on ancestral chromosomes, and demonstrate that the ancestral Cucumis karyotype (n = 12) evolved to extant Cucumis genomes by hybridizations and frequent lineage- and species-specific genome reshuffling. Relative to the African species, the Asian species, including melon (Cucumis melo, n = 12), Cucumis hystrix (n = 12) and cucumber (Cucumis sativus, n = 7), had highly shuffled genomes caused by large-scale inversions, centromere repositioning and chromothripsis-like rearrangement. The deduced reconstructed ancestral karyotype for the genus allowed us to propose evolutionary trajectories and specific events underlying the origin of these Cucumis species. Our findings highlight that the partitioned evolutionary plasticity of Cucumis karyotype is primarily located in the centromere-proximal regions marked by rearrangement hotspots, which can potentially serve as a reservoir for chromosome evolution due to their fragility.     

Differences in motivations and weight loss behaviors in young adults and older adults in the national weight control registry

Objective:

The goal of this study was to compare young adults (YA) and older adults (OA) in the National Weight Control Registry on motivations for weight loss and weight‐loss behaviors.

Design and Methods:

Participants (n = 2,964, 82% female, 94% White, BMI = 24.8 ± 4.4) were divided into two age groups (18‐35 vs. 36‐50) and compared on motivations, strategies for weight loss, diet, physical activity (PA), and the three‐factor eating questionnaire.

Results:

YA were 28.6% of the sample (n = 848). YA and OA achieved similar weight losses (P = 0.38), but duration of maintenance was less in YA (43 vs. 58 months, P < 0.001). YA were more likely to cite appearance and social motivations for weight loss, were less motivated by health, and were less likely to report a medical trigger for weight loss (P's < 0.001). YA were more likely to use exercise classes and to lose weight on their own, and less likely to use a commercial program (P's < 0.001). YA reported engaging in more high‐intensity PA (P = 0.001). There were no group differences in total calories consumed (P = 0.47), or percent calories from fat (P = 0.97), alcohol (P = 0.52), or sugar‐sweetened beverages (P = 0.26).

Conclusions:

YA successful weight losers (SWL) are motivated more by appearance and social influences than OA, and physical activity appears to play an important role in their weight‐loss efforts. The differences reported by YA and OA SWL should be considered when developing weight‐loss programs for YA.     

Weight Loss Expectations in Obese Patients Seeking Treatment at Medical Centers

Objective: To investigate weight loss expectations (expected 1‐year BMI loss, dream BMI, and maximum acceptable BMI) in obese patients seeking treatment and to examine whether expectations differ by sex, weight, diet and weight history, age, psychological factors, and primary motivations for weight loss. Research Methods and Procedures: 1891 obese patients seeking treatment in 25 Italian medical centers (1473 women; age, 44.7 ± 11.0 years; BMI, 38.2 ± 6.5 kg/m²) were evaluated. Diet and weight history, weight loss expectations, and primary motivation for seeking treatment (health or improving appearance) were systematically recorded. Psychiatric distress, binge eating, and body image dissatisfaction were tested by self‐administered questionnaires (Symptom CheckList‐90, Binge Eating Scale, and Body Uneasiness Test). Results: In 1011 cases (53.4%), 1‐year expected BMI loss was ≥9 kg/m², dream BMI was 26.0 ± 3.4 kg/m² (corresponding to a 32% loss), and maximum acceptable BMI was 29.3 ± 4.4 kg/m² (?23%). BMI and age were the strongest predictors of weight goals. Weight loss necessary to reach the desired targets was largely in excess of weight loss observed during previous dieting. Psychiatric distress, body dissatisfaction, and binge eating did not predict weight loss expectations. The primary motivation for weight loss was concern for future or present health; women seeking treatment to improve appearance had a lower grade of obesity, were younger, and had first attempted weight loss at a younger age. Discussion: Obese Italian patients had unrealistic weight loss expectations. There were significant disparities between patients’ perceptions and physicians’ weight loss recommendations of desirable treatment outcome.     

Tomato <Emphasis Type="Italic">fruit weight 11.3</Emphasis> maps close to <Emphasis Type="Italic">fasciated</Emphasis> on the bottom of chromosome 11

Fruit weight is an important character in many crops. In tomato (Solanum lycopersicum), fruit weight is controlled by many loci, some of which have a major effect on the trait. Fruit weight 11.3 (fw11.3) and fasciated (fas) have been mapped to the same region on chromosome 11. We sought to determine whether these loci represent alleles of the same or separate genes. We show that fas and fw11.3 are not allelic and instead represent separate genes. The fw11.3 locus was fine-mapped to a 149-kb region comprised of 22 predicted genes. Unlike most fruit weight loci, gene action at fw11.3 indicates that the mutant allele is partially dominant over the wild allele. We also investigate the nature of the genome rearrangement at the fas locus and demonstrate that the mutation is due to a 294-kb inversion disrupting the YABBY gene known to underlie the fas locus.     

Meiosis in Sxr male mice

Cytological evidence for the existence of a Y-autosomal rearrangement in meiotic cells of Sxr mice has been sought. At pachytene, in silverstained light microscope spread preparations of XY, Sxr/+ and XO, Sxr/+ spermatocytes, evidence for pairing or association between a possible Y-bearing segment of a specific autosome and a sex chromosome could not, however, be found. Such sex chromosome-autosome associations as were seen were non-specific in nature, and occurred no more often in Sxr mice than in controls.     

Weight Loss Expectations in Patients with Binge‐Eating Disorder

Objective: To study weight loss expectations in patients with binge‐eating disorder and to examine whether expectations differed by sex and motivation for treatment. Research Methods and Procedures: One hundred and thirty patients (104 women and 26 men), aged 23 to 61 (mean age, 43.0 years), with BED completed a measure of desired weights that included their dream weight, happy weight, acceptable weight, and disappointed weight. In a structured interview, participants were asked their primary motivation for seeking treatment (appearance or health) and their lowest adult weight (LAW). Results: The BED participants reported weight loss expectations that far exceeded expert and governmental guidelines. In this sample, desired dream body mass index (BMI), happy BMI, and acceptable BMI averaged reductions in current weight of 36%, 29%, and 23%, respectively. Even the “disappointed” BMI was an average 14% reduction in current weight, and was 1.5 to 3 times greater than the expert recommendation (5% to 10%). Comparisons of desired weights were significantly different for women and men, whereas percent reductions from current weight were not. Although weight goal expectations were significantly lower for those motivated by appearance, compared with those motivated by health, percent reductions for current weight were not. Desired dream weight correlated with reported LAW, and the mean difference between these weights was not significant. Discussion: These findings suggest that patients with BED have weight loss expectations that far exceed expert and governmental guidelines and that these expectations do not differ by sex or motivation for seeking treatment. One possible explanation for these unrealistic desired weights may be the patients’ recollections of their LAWs.     

Effects of gastric bypass and gastric banding on glucose kinetics and gut hormone release

Background: Bariatric surgery markedly improves glucose homeostasis in patients with type 2 diabetes even before any significant weight loss is achieved. Procedures that involve bypassing the proximal small bowel, such as Roux‐en‐Y gastric bypass (RYGBP), are more efficient than gastric restriction procedures such as gastric banding (GB). Objective: To evaluate the effects of RYGBP and GB on postprandial glucose kinetics and gastro‐intestinal hormone secretion after an oral glucose load. Methods and Procedures: This study was a cross‐sectional comparison among non‐diabetic, weight‐stable women who had undergone RYGBP (n = 8) between 9 and 48 months earlier or GB (n = 6) from 25 to 85 months earlier, and weight‐ and age‐matched control subjects (n = 8). The women were studied over 4 h following ingestion of an oral glucose load. Total glucose and meal glucose kinetics were assessed using glucose tracers and plasma insulin, and gut hormone concentrations were simultaneously monitored. Results: Patients who had undergone RYGBP showed a a more rapid appearance of exogenous glucose in the systemic circulation and a shorter duration of postprandial hyperglycemia than patients who had undergone GB and C. The response in RYGBP patients was characterized by early and accentuated insulin response, enhanced postprandial levels of glucagon‐like peptide‐1 (GLP‐1) and polypeptide YY (PYY), and greater postprandial suppression of ghrelin. Discussion: These findings indicate that RYGBP is associated with alterations in glucose kinetics and glucoregulatory hormone secretion. These alterations are probably secondary to the anatomic rearrangement of the foregut, given the fact that they are not observed after GB. Increased PYY and GLP‐1 concentrations and enhanced ghrelin suppression are compatible with reduced food intake after RYGBP.     

Molecular and biological studies on male-sterile cytoplasm in the Cruciferae. I. The origin and distribution of Ogura male-sterile cytoplasm in Japanese wild radishes (Raphanus sativus L.) revealed by PCR-aided assay of their mitochondrial DNAs

Ogura male-sterile cytoplasm was surveyed in common Japanese radish cultivars and in wild radishes growing in various localities in Japan. Mitochondrial (mt) DNA rearrangement involving the atp6 gene was used as a molecular marker. To detect the mtDNA rearrangement, polymerase chain reactions (PCR) were designed to amplify the upstream region of the atp6 gene. The oligonucleotides homologous to the following three regions were synthesized: (1) trnfM, (2) ORF105 and (3) atp6. PCRs were conducted with a pair of the first and the third primers to detect normal mtDNA, and with the second and the third primers for Ogura-type mtDNA. All 15 Japanese cultivars yielded an amplification product which was the same as that of normal mtDNA, whereas some wild radishes gave the product specific to Ogura mtDNA. Twenty-four populations of wild radish were classified into three groups according to the frequency of Ogura-type mtDNA: (1) in ten populations, all four plants analyzed per population had normal type mtDNA, (2) in five populations, only plants with Ogura-type mtDNA were found, and (3) nine populations included both normal and Oguratype mtDNAs. There were no geographical restrictions and no cline in the distribution of the plants with Ogura-type mtDNA. These results suggested that the Ogura-type male-sterile cytoplasm originated in wild radishes.     

Regulated DNA rearrangement during sporulation in Bacillus weihenstephanensis KBAB4

Temperate phages can integrate their genomes into a specific region of a host chromosome to produce lysogens (prophage). During genome insertion, prophages may interrupt the gene coding sequence. In Bacillus subtilis, the sigma factor gene sigK is interrupted by a 48 kb prophage‐like element. sigK is a composite coding sequence from two partial genes during sporulation. For over two decades, however, no further examples of DNA element‐mediated gene reconstitution other than sigK have been identified in spore formers. Here we report that the gene for dipicolinic acid (DPA) synthetase β subunit spoVFB in B. weihenstephanensis KBAB4 is interrupted by a prophage‐like element named vfbin. DPA is synthesized in the mother cell and required for maintaining spore dormancy. We found that spoVFB was a composite coding sequence generated in the mother cell via chromosomal rearrangement that excised vfbin. Furthermore, vfbin caused excision after phage‐inducer treatment, but vfbin appeared to be defective as a prophage. We also found various spore‐forming bacteria in which sporulation‐related genes were disrupted by prophage‐like DNA elements. These results demonstrate the first example of a similar mechanism that affects a sporulation gene other than sigK and suggest that this prophage‐mediated DNA rearrangement is a common phenomenon in spore‐forming bacteria.     

A comparison of within-plant karyological heterogeneity between agamospermous and sexualTaraxacum (Compositae) as assessed by the nucleolar organiser chromosome

Morphological variation for the NOR chromosome was studied for four half-siblings of a sexual outbreedingTaraxacum, for three siblings of the obligate agamospermT. pseudohamatum, and for two individuals of the agamospermT. brachyglossum. No rearrangement was detected for the 113 chromosomes of sexuals, or for 41 chromosomes of two agamospermous individuals. In the other three agamospermous individuals, 3/16, 5/50, and 5/20 chromosomes showed evidence of chromosomal rearrangement. The majority of rearrangement events (10/13) occurred to the satellite rather than to the body of the NOR-chromosome. It is considered that such high levels of somatic chromosomal rearrangement in agamospermousTaraxacum may be the result of activity by transposable genetic elements. This recombination may be of selective advantage to asexual plants which cannot generate genetic variability through the sexual process.