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61.
The pathogenicity of a recently isolated strain of T. foetus in mice was studied. The parasite produced local abscesses 3 days post subcutaneous inoculation (p.i.) in albino mice. The abscesses in mice, inoculated with large numbers (4 × 106) of organisms, continued increasing in size until the 14th day. Some absceses ruptured between day 11 to 14 p.i., while others formed a point. Secondary abscesses were also found in some mice. the abscesses in mice, inoculated with small numbers (1 × 106) of organisms reached their maximum on the 5th day and decreased thereafter. All the abscesses had motile trichomonads with no bacterial contamination. The trichomonads, inoculated intraperitoneally in mice, persisted in that cavity till day 5 or 6 p.i., but did not multiply. Subcutaneous inoculations appear to be more reliable than the intraperitoneal ones for studies on pathogenicity. The comparison of present observations with those using a similar model and T. foetus or other trichomonads, suggests that the strain of T. foetus employed was of low pathogenicity.  相似文献   
62.
The regulation of photosynthesis by its assimilates was investigated in sunflower by altering the assimilate level in leaves by girdling, detopping, shading and defoliation. The level of assimilates like sucrose accumulated in leaves did not inhibit photosynthesis or Rubisco activity. Starch levels also did not have an influence on the photosynthetic rate.  相似文献   
63.
64.
Ghrelin, a novel motilin-related endogenous ligand for growth hormone secretagouge receptor, is implicated in various biological functions, including regulation of female reproduction. But the presence of ghrelin and its role in reproductive functions in buffalo, a species with poor reproductive efficiency, is not known. In the present study full-length ghrelin cDNA was isolated from bubaline abomasum, which encodes the entire prepropeptide of 116 amino acids. The deduced amino acid sequence of ghrelin of buffalo showed >95% and 31% identity with that of ruminants (cattle, sheep, and goat) and humans, respectively. Analysis of synonymous and nonsynonymous nucleotide substitutions in the coding region of ghrelin indicated that these sequences of different species have been under purifying selection. The 3995-bp amplicon of ghrelin gene consisting of 4 exons and 3 introns was cloned with genomic DNA from buffalo. Further, ghrelin expression was determined by quantitative real-time PCR, in situ hybridization, and immunohistochemistry in bubaline endometrial tissues at different stages of the estrous cycle and early pregnancy. Our results indicated the persistent expression of ghrelin mRNA and protein in the endometrium during stage I (day 3–5), stage II (day 6–15), and stage III (day 16–21) of the estrous cycle and also during early (∼day 30–40) pregnancy. Immunohistochemistry and quantitative real-time PCR experiments indicated the relatively higher expression of ghrelin in the endometrium during stage II (day 6–15) of the estrous cycle and early pregnancy than during stage I (day 3–5) and stage III (day 16–21) of the estrous cycle, but no statistically significant difference in ghrelin expression was observed among stages. To conclude, the results of the present study indicate the persistent expression of ghrelin in the uterine endometrium throughout the estrous cycle and in early pregnancy which might be helpful in determining its role in buffalo reproduction.  相似文献   
65.
Solena amplexicaulis (Lam.) Gandhi (Cucurbitaceae) is a promising vegetable in Southeast Asia. Infestation of Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) adults on leaves of the crop plant causes death of the plant and reduces crop production. Currently, growers are applying insecticides to control this pest, which are harmful to health and environment. Hence, an attempt has been made to find out allelochemicals from leaves attracting the insect, which might be used for ecofriendly pest management program. The emission of volatiles was detected from undamaged leaves of herbivore-induced plants after 24 h and 120 h of continuous females feeding on lower leaves of the same plants by GC-MS and GC-FID analysis. The insect showed attraction to systemically released volatiles from herbivore-induced plants against unharmed plants in Y-shaped glass tube olfactometer bioassays. The insect was attracted to a synthetic blend of 1.2 µg linalool oxide + 3.2 µg nonanal + 1.5 µg trans-2-nonenal dissolved in 20 µL CH2Cl2 in olfactometer and wind tunnel bioassays, and hence, this blend could be used in development of baited traps in pest management strategies.  相似文献   
66.
Background

The relationships between group size, survival, and longevity vary greatly among social species. Depending on demographic and ecological circumstances, there are both positive and negative effects of group size variation on individual survival and longevity. For socially foraging species in particular there may be an optimal group size that predicts maximum individual survival that is directly related to the potential for information transfer, social coordination, and costs of conspecific interference. Our aim was to investigate this central aspect of evolutionary ecology by focusing on a socially foraging bat, Molossus molossus. This species optimizes foraging success by eavesdropping on the echolocation calls of group members to locate ephemeral food patches. We expected to find the highest survival and longest lifespans in small groups as a consequence of a trade-off between benefits of information transfer on ephemeral resources and costs of conspecific interference.

Results

In a mark-recapture study of 14 mixed-sex M. molossus social groups in Gamboa, Panama, spanning several years we found the expected relatively small and intermediate, but stable groups, with a mean size of 9.6 ± 6.7 adults and juveniles. We estimated survival proxies using Cox proportional hazard models and multistate-mark recapture models generated with recapture data as well as automated monitoring of roost entrances in a subset of the groups. Median survival of females was very short with 1.8 years and a maximum estimated longevity of 5.6 years. Contrary to our expectations, we found no relationship between variation in group size and survival, a result similar to few other studies.

Conclusions

Strong selection towards small group size may result from psychoacoustic and cognitive constraints related to acoustic interference in social foraging and the complexity of coordinated flight. The short lifespans were unexpected and may result from life at the energetic edge due to a highly specialized diet. The absence of a relationship between group size and survival may reflect a similar but optimized survival within the selected range of group sizes. We expect the pattern of small group sizes will be consistent in future research on species dependent on social information transfer about ephemeral resources.

  相似文献   
67.
Hyperglycemia causes increased protein glycation and the formation of early glycation products and advanced glycation end products (AGEs) which are major factors responsible for the complications associated with diabetes. The aim of the present study was to investigate the antioxidant as well as antiglycative potential of ethyl acetate fraction of guava leaves. Oral administration of the extract at different doses showed a significant decrease in blood glucose level. It also showed an improved antioxidant potential as evidenced by decreased lipid peroxidation and a significant increase in the activity of various antioxidant enzymes such as catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase. Glycated hemoglobin as well as fructosamine which are indicators of glycation was also reduced significantly in treated groups when compared to diabetic control. In vitro studies also support the antioxidant as well as antiglycative potential of guava leaves.  相似文献   
68.
Effect of various dietary protein levels on growth and nutrient utilization were studied in fringe‐lipped carp, Labeo fimbriatus fingerlings for 60 days. Five practical diets containing graded protein levels of 200, 250, 300, 350 and 400 g kg?1 with respective digestible protein (DP) contents of 192.4, 244.5, 291.6, 339.4 and 391.4 g kg?1 were evaluated as five treatments, T1, T2, T3, T4 and T5, respectively, in triplicate. Each experimental tank (80‐L) contained eight fingerlings (4.9 ± 0.1 g) and was subjected to continuous aeration and 25% water replenishment daily. The fish were fed two times daily at 8:00 and 14:00 h to satiation. Significantly higher (< 0.05) absolute growth and thermal growth coefficient, and lower feed conversion ratios (FCR) were observed in T2–T4 than T1 and T5. Protein efficiency ratio (PER) and protein productive values (PPV) were highest in T2 and lowest in T5. Significantly higher (< 0.05) apparent protein digestibility was perceptible in T2–T4. While specific amylase activity declined linearly with increasing DP : DE, the protease, trypsin, aspartate aminotransferase and alanine aminotransferase established polynomial relationship. Based on live weight gain, PER and PPV fitted to quadratic model optimum DP levels were estimated as 301.4, 260.0 and 273.0 g kg?1, respectively.  相似文献   
69.
Arsenic (As) species were quantified by HPLC-HG-AFS in water and vegetables from a rural area of West Bengal (India). Inorganic species predominated in vegetables (including rice) and drinking water; in fact, inorganic arsenic (i-As) represented more than 80% of the total arsenic (t-As) content. To evaluate i-As intake in an arsenic affected rural village, a food survey was carried out on 129 people (69 men and 60 women). The data from the survey showed that the basic diet, of this rural population, was mainly rice and vegetables, representing more than 50% of their total daily food intake. During the periods when nonvegetarian foods (fish and meat) were scarce, the importance of rice increased, and rice alone represented more than 70% of the total daily food intake. The food analysis and the food questionnaires administrated led us to establish a daily intake of i-As of about 170 microg i-As day (-1), which was above the tolerable daily intake of 150 microg i-As day (-1), generally admitted. Our results clearly demonstrated that food is a very important source of i-As and that this source should never be forgotten in populations depending heavily on vegetables (mainly rice) for their diet.  相似文献   
70.
Alzheimer’s disease (AD) is a devastating neurodegenerative disease and the most common cause of dementia. It has been confirmed that the pathological processes that intervene in AD development are linked with oxidative damage to neurons, neuroinflammation, tau phosphorylation, amyloid beta (Aβ) aggregation, glutamate excitotoxicity, and cholinergic deficit. Still, there is no available therapy that can cure AD. Available therapies only manage some of the AD symptoms at the early stages of AD. Various studies have revealed that bioactive compounds derived from marine organisms and plants can exert neuroprotective activities with fewer adverse events, as compared with synthetic drugs. Furthermore, marine organisms have been identified as a source of novel compounds with therapeutic potential. Thus, there is a growing interest regarding bioactive compounds derived from marine sources that have anti-AD potentials. Various marine drugs including bryostatin-1, homotaurine, anabaseine and its derivative, rifampicins, anhydroexfoliamycin, undecylprodigioisin, gracilins, 13-desmethyl spirolide-C, and dictyostatin displayed excellent bioavailability and efficacy against AD. Most of these marine drugs were found to be well-tolerated in AD patients, along with no significant drug-associated adverse events. In this review, we focus on the drugs derived from marine life that can be useful in AD treatment and also summarize the therapeutic agents that are currently used to treat AD.  相似文献   
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