The current situation of small and medium-sized industrial enterprises in Trinidad & Tobago, Barbados and St. Lucia

Includes bibliography

Availability, collection and use of data on disability in the Caribbean subregion

Includes bibliography

Effect of fungicides on the mite fauna of prunus persica L. cultivars in Presidente Prudente, SP, Brazil

The objective of this study was to characterize the diversity of phytophagous and predatory mites on peach cultivars either with or without fungicide treatment, in the city of Presidente Prudente, State of São Paulo, Brazil. In order to evaluate the effect of fungicides, leaf samples were colleted at random from treated and untreated plants of the Tropical, Aurora 1 and Aurora 2 cultivars, from June 2004 to February 2006. From the results obtained it can be concluded that: plants with or without treatment showed high populations of predatory mites, indicating that the treatments were innocuous on the mite populations. A diversified composition of the mite community was observed. The Phytoseiidae family had the highest richness in numbers and species of mites. Euseius citrifolius and E. concordis were the most abundant species. Plants with or without treatment had high abundances of predatory mites, with a predominance of E. citrifolius.

Side-effects of thiamethoxam on the brain andmidgut of the africanized honeybee Apis mellifera (Hymenopptera: Apidae)

The development of agricultural activities coincides with the increased use of pesticides to control pests, which can also be harmful to nontarget insects such as bees. Thus, the goal of this work was assess the toxic effects of thiamethoxam on newly emerged worker bees of Apis mellifera (africanized honeybee-AHB). Initially, we determined that the lethal concentration 50 (LC50) of thiamethoxam was 4.28 ng a.i./μL of diet. To determine the lethal time 50 (LT50), a survival assay was conducted using diets containing sublethal doses of thiamethoxam equal to 1/10 and 1/100 of the LC50. The group of bees exposed to 1/10 of the LC50 had a 41.2% reduction of lifespan. When AHB samples were analyzed by morphological technique we found the presence of condensed cells in the mushroom bodies and optical lobes in exposed honeybees. Through Xylidine Ponceau technique, we found cells which stained more intensely in groups exposed to thiamethoxam. The digestive and regenerative cells of the midgut from exposed bees also showed morphological and histochemical alterations, like cytoplasm vacuolization, increased apocrine secretion and increased cell elimination. Thus, intoxication with a sublethal doses of thiamethoxam can cause impairment in the brain and midgut of AHB and contribute to the honeybee lifespan reduction. © 2013 Wiley Periodicals, Inc.

The external debt of the Latin American countries

También en: Comercio Exterior, México, DF, v. 36, No 5, p. 382, mayo 1986 (78609); y en: U.S. Congress. House. Committee on Banking, Finance and Urban Affairs: The costs of foreign debt for the United States and the Third World, Washington, DC

The effects of pinning on critical currents of superconducting films

Using molecular dynamics simulations, we analyze the effects of artificial periodic arrays of pinning sites on the critical current of superconducting thin films as a function of vortex density. We analyze two types of periodic pinning array: hexagonal and Kagomé. For the Kagome pinning network we make calculations using two directions of transport current: along and perpendicular to the main axis of the lattice. Our results show that the hexagonal pinning array presents higher critical currents than the Kagomé and random pinning configuration for all vortex densities. In addition, the Kagomé networks show anisotropy in their transport properties. © 2012 Springer Science+Business Media, LLC.

Role of brain nitric oxide in the cardiovascular control of bullfrogs

The goal of the present study was to determine if nitric oxide (NO) acting on the brain of bullfrog (Lithobates catesbeianus) is involved in arterial pressure and heart rate (HR) control by influencing sympathetic activity. We investigated the effect of intracerebroventricular injections of l-NMMA (a nonselective NO synthase inhibitor) on mean arterial blood pressure (MAP), HR and cutaneous vascular conductance (CVC) of pelvic skin after intravenous injection of α or β adrenergic blockers, prazosin or sotalol, respectively. Arterial pressure was directly measured by a telemetry sensor inserted in the aortic arch of animals. l-NMMA increased MAP, but did not change HR. This hypertensive response was inhibited by the pre-treatment with prazosin, but accentuated by sotalol. The effect of l-NMMA on MAP was also inhibited by i.v. injections of the ganglionic blocker, hexamethonium. Thus, NO acting on the brain of bullfrog seems to present a hypotensive effect influencing the sympathetic activity dependent on α and β adrenergic receptors in the periphery. © 2013 Elsevier Inc.

Assessing the impact of menopause on salivary flow and xerostomia

Background: The aim of this study was to evaluate the symptoms of dry mouth and salivary flow in menarche and menopausal women. Methods: Objective and subjective assessment of salivary function were analysed by Xerostomia Inventory and Visual Analogue Scale questionnaire in menopausal and menarche women (control group). Salivary flow was evaluated by a chemical absorption stimulation test. Each subject provided three saliva samples: S1, non-stimulated saliva; S2, saliva initially stimulated with two drops of citric acid 2.5%; and S3, saliva super-stimulated with two drops of citric acid 2.5% every 30 seconds for two minutes. Results: No intergroup association was observed between Xerostomia Inventory and Visual Analogue Scale questionnaire. In both groups, the salivary flow was greatest at S3, followed by S2 and finally S1. Salivary flow was lower in the menopausal group compared to the control group only in S2 and S3. Conclusions: In the menopausal group, the salivary flow showed reduction but without clinical symptoms of dry mouth. It is important to normalize salivary flow to prevent oral abnormalities and maintain oral health. © 2013 Australian Dental Association.

Inhibitory mechanism of the nucleus of the solitary tract involved in the control of cardiovascular, dipsogenic, hormonal, and renal responses to hyperosmolality

The nucleus of the solitary tract (NTS) is the primary site of visceral afferents to the central nervous system. In the present study, we investigated the effects of lesions in the commissural portion of the NTS (commNTS) on the activity of vasopressinergic neurons in the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei, plasma vasopressin, arterial pressure, water intake, and sodium excretion in rats with plasma hyperosmolality produced by intragastric 2 M NaCl (2 ml/rat). Male Holtzman rats with 15-20 days of sham or electrolytic lesion (1 mA; 10 s) of the commNTS were used. CommNTS lesions enhanced a 2 M NaCl intragastrically induced increase in the number of vasopressinergic neurons expressing c-Fos in the PVN (28 ± 1, vs. sham: 22 ± 2 c-Fos/AVP cells) and SON (26 ± 4, vs. sham: 11 ± 1 c-Fos/AVP cells), plasma vasopressin levels (21 ± 8, vs. sham: 6.6 ± 1.3 pg/ml), pressor responses (25 ± 7 mmHg, vs. sham: 7 ± 2 mmHg), water intake (17.5 ± 0.8, vs. sham: 11.2 ± 1.8 ml/2 h), and natriuresis (4.9 ± 0.8, vs. sham: 1.4 ± 0.3 meq/1 h). The pretreatment with vasopressin antagonist abolished the pressor response to intragastric 2 M NaCl in commNTS-lesioned rats (8 ± 2.4 mmHg at 10 min), suggesting that this response is dependent on vasopressin secretion. The results suggest that inhibitory mechanisms dependent on commNTS act to limit or counterbalance behavioral, hormonal, cardiovascular, and renal responses to an acute increase in plasma osmolality. © 2013 the American Physiological Society.

Effects of methylmercury on electric organ discharges in the weak electric fish Gymnotus sylvius

Methylmercury (MeHg) is present in the environment because of natural and anthropogenic causes. MeHg can reach the central nervous system (CNS) and cause neurological damage in humans and animals. Electric organ discharges (EODs) in the weak electric fish Gymnotus sylvius are produced by the electric organ and modulated by the CNS. These discharges are used for electrolocation and communication. The purpose of the present study was to investigate the effects of dietary MeHg exposure on EOD rate in G. sylvius. An oscilloscope was used to record the EOD rate. Two treatments were investigated: chronic MeHg administration (4 μg/kg MeHg every 2 days, with a total of nine dietary exposures to MeHg) and acute MeHg administration (a single dose of 20 μg/kg MeHg). The control data for both treatments were collected every 2 days for 18 days, with a total of nine sessions (day 1 until day 18). Data of fish exposed to MeHg were collected every 2 days, totaling nine sessions (day 19 until day 36). Chronic treatment significantly increased the EOD rate in G. sylvius (p<.05), especially with the final treatment (day 32 until day 36). Acute treatment resulted in an initial increase in the EOD rate, which was maintained midway through the experiment (day 26 until day 30 p<.05). The present study provides the first insights into the effects of MeHg on EODs in weak electric fish. The EOD rate is a novel response of the fish to MeHg administration.

The action of aminoguanidine on the liver of trained diabetic rats

Background: This study evaluated the effect of aminoguanidine on liver of diabetic rats subject to physical exercises using histological and histochemical techniques.Methods: The rats used in this study were divided into five groups: sedentary control, sedentary diabetic, trained diabetic, sedentary diabetic and treated with aminoguanidine, trained diabetic and treated with aminoguanidine.Results: The results showed no effect of aminoguanidine on the liver tissue, although there was improvement with exercise training showing cytological, morpho-histological and histochemical alterations in liver cells of animals from groups trained diabetic and/or treated diabetic compared to those individuals in the sedentary control and sedentary diabetic. These changes included: hepatocytes hypertrophy, presence and distribution of polysaccharides in the hepatocytes cytoplasm and, especially, congestion of the liver blood vessels.Conclusion: Our results suggest that aminoguanidine is not hepatotoxic, when used at dosage of 1 g/L for the treatment of diabetes complications, and confirmed that the practice of moderate physical exercise assuaged the damage caused by diabetes without the use of insulin. © 2013 e Nico et al.; licensee BioMed Central Ltd.

Systematic review of the effects of fatigue on spatiotemporal gait parameters

PURPOSE: This systematic review aimed to assess changes on spatiotemporal gait parameters due to fatigue. MATERIAL AND METHOD: A search was carried out in literature published from 1950 to December 2010 and retrieved 771 articles using terms referring to walking and fatigue in the title, abstract or keywords. Two researchers assessed the selection and quality of each article independently. RESULTS: Seven studies were selected for this systematic review, two of which reported on the same data set. Several spatiotemporal parameters were reported to change with fatigue, but the few variables studied in multiple studies, gait speed and stride or step length and stride time, were affected only in single studies. Fatigue appears to modulate spatiotemporal gait parameters, but the effects of fatigue appear to be dependent on the muscles that were fatigued, and age that appears to be a moderator of the effects of fatigue on gait. © 2013 - IOS Press and the authors. All rights reserved.

Chemical control of pathogens and the physiological performance of peanut seeds

The establishment of a peanut crop may be unsatisfactory due to poor seed performance in the field and among the factors attributed to this are a reduction in seed vigor during storage and the presence of pathogens. The objective of this study was to evaluate the efficiency of treating peanut seeds with fungicides and the effect on physiological performance and disease control during storage. In a completely random experimental design, two seed batches of the Runner IAC 886 peanut cultivar were submitted to five fungicide treatments (1 control - untreated; 2 thiram; 3 carbendazim + thiram; 4 fludioxonil + metalaxyl-m; 5 fludioxonil + mefenoxam + thiabendazole) and evaluated after zero, 30 and 60 days of storage. The seeds were stored untreated but treated before the evaluation of physiological performance from germination, vigor (first germination count and accelerated aging), field seedling emergence and seed sanitation tests. The results showed differences in batch performance potential during storage, with batch 1 being superior. The sanitation test showed that all the chemical seed treatments controlled pathogens efficiently (Aspergillus spp. and Penicillium sp.), but only thiram did not affect peanut seed performance in the laboratory evaluations.

Effect of muscle fatigue and physical activity level in motor control of the gait of young adults

The aim of this study was to analyze the effect of muscle fatigue in active and inactive young adults on the kinematic and kinetic parameters of normal gait and obstacle crossing. Twenty male subjects were divided into active (10) and inactive (10), based on self-reported physical activity. Participants performed three trials of two tasks (normal gait and obstacle crossing) before and after a fatigue protocol, consisting of repeated sit-to-stand transfers until the instructed pace could no longer be maintained. MANOVAs were used to compare dependent variables with the following factors: physical activity level, fatigue and task. The endurance time in the fatigue protocol was lower for the inactive group. Changes of gait parameters with fatigue, among which increased step width and increased stride speed were the most consistent, were independent of task and physical activity level. These findings indicate that the kinematic and kinetic parameters of gait are affected by muscle fatigue irrespective of the physical activity level of the subjects and type of gait. Inactive individuals used a slightly different strategy than active individuals when crossing an obstacle, independently of muscle fatigue. © 2013.

Hispanic poverty from the current population survey and poverty of other self-identified ethnic groups from census information

Includes bibliography