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The academy has given little attention to academically successful Black males and the factors that may lead to their successes. This multiple case study design, however, examined the ways in which single-Black mothers influence the educational success of their sons by focusing on the mothers of academically successful 11th grade Black males. Data for this study came from in-person tape-recorded interviews conducted with each mother followed by a focus group. Results support the existence of common characteristics of these successful single Black mothers and the strategies they use to help their sons beat the odds. Recommendations for school leaders are also given. [ABSTRACT FROM AUTHOR]

Abstract: Background: With more than a million youth living on agricultural operations, it is important for parents to understand the consequences of bystander injuries that children experience in these environments. We identified the childhood injuries for bystander status and compared the severity of these injuries to the working children in the Regional Rural Injury Study-II (RRIS-II). Methods: RRIS-II followed 16,546 children (∼85% of eligible) from rural communities in the Midwest for two six-month recall periods in 1999 and 2001. Demographic, injury, and exposure data were collected through comprehensive computer-assisted telephone interviews. Child injuries were cataloged using narrative scenarios into four categories: (a) directly work-related; (b) indirectly work-related; (c) non-working accomplice; and (d) non-working attendant; the latter three all being bystander categories. Poisson regression modeling was used to calculate rates of bystander injuries. Frequencies were used for comparison of severity measures. Results: Among the 463 child injuries (aged <20yrs), 102 were bystander injuries. Of the bystander-related injuries, 14 were identified as indirectly work-related (working bystanders), 27 as non-working accomplice (passengers/tag-alongs), and 60 as non-working attendant (playing on the operation). The overall rate of bystander injuries was 6.4 per 1,000 people, 95% CI (5.0, 8.1). Males, compared with females, had more than twice the injury rate (8.7; 95% CI 6.4-11.8, and 3.9; 95% CI 2.7-5.7, per 1,000 people, respectively). Bystanders in this population had more severe injuries with 4% having life-threatening circumstances; of these, 4% of the accomplices and 2% of the attendants subsequently died. Conclusions: Children who live or work on agricultural operations are vulnerable to many hazards. Therefore, this study examined child injuries and found a clear difference in the consequences of these injuries between working-related and bystanding-related injuries. Impact on Industry: Unlike occupations such as construction and mining, where laws and organizations have been created for the protection of bystanders, agricultural bystanders have remained unprotected and have had to face the consequent injury and death outcomes. As public health professionals considering these risks, it is necessary that we work to develop more intervention studies and continue to propose suggestive guidelines for child safety in these environments so as to challenge family traditions and possibly spark public policies that will give further protection to this population. [Copyright &y& Elsevier]

Abstract: Background: Agriculture is considered among the most dangerous occupations and has consistently ranked among the top three. Production processes, associated with this occupation, place at risk not only workers but also others who live on the operations. We evaluated the incidence and determinants of associated bystander injuries in the Regional Rural Injury Study-II (RRIS-II). Methods: The RRIS-II followed 32,601 people (∼85% of eligible) from rural communities in the Midwest for 1999 and 2001, using six-month recall periods, and identified their injury events. Demographic, injury, and exposure data were collected through comprehensive and case–control computer-assisted telephone interviews. Multivariate logistic regression analyses were used to estimate the risk of child bystanding and agricultural injury, while controlling for potentially confounding variables. Results: Nearly 60% of all 425-child injury cases (<20 years) responded to sometimes/frequently bystanding in six out of seven different agricultural environments (e.g., workshops, animal areas, etc.) Multivariate regression analyses, with odds ratios and 95% confidence intervals, showed increased odds of injury for bystanding near used (1.5; 1.1, 1.9) or stored (1.4; 1.1, 1.8) machinery, and near fields and barnyards (1.4; 1.0, 1.9). Further, multivariate analyses revealed increased odds of bystanding for parental beliefs, such as: child age (1.4; 1.0, 2.0) near stored equipment. Parental levels of strictness were also evaluated and showed decreased odds of bystanding when the parents were not strict about the child''s wearing a seatbelt near used equipment (0.5; 0.3, 1.0). Households with only one child had decreased odds of bystanding for five of the exposures while there was an increased odds of bystanding near animals for households with five or more children. Conclusions: Although parents cannot child-proof their operations, it is important for them to understand the apparent odds of and risks associated with bystanding. Children can have injury odds similar to adults in this environment; therefore, it is necessary to examine parental factors that may be associated with children''s likelihood of bystanding in high-risk work environments. [Copyright &y& Elsevier]

Abstract: This study explored the characteristics of the Borderline Personality Disorder classification, specified in DSM-III. MMPI profiles of 29 male veteran inpatients with a diagnosis of Borderline Personality Disorder were compared with the profiles of 26 similar inpatients with diagnoses of other personality disorders. The borderline group had higher elevations (P < 05) on six of the 13 standard MMPI scales. Analyses showed the borderline .. u profiles to be of a significantly higher elevation but no different m either profile shape or dispersion. A discriminant analysis accounted for 43.7.% of the variance and correctly clas- sified 78.2% of the patients. Results are discussed in terms of possible explanations for the high F scores of the borderline group. Implications regarding characteristics of the Border- u line Personality Disorder are discussed. [ABSTRACT FROM AUTHOR]

Historically, surgical instruments were designed by men for male surgeons. Although instrumentation has changed with the changing paradigms of surgery, it has failed to adapt to the changing surgical workforce. Almost 30% of surgeons are female and nearly 90% of surveyed female surgeons report poor instrument design and associated musculoskeletal injuries from use. Understanding the current state of handheld surgical instrument design, published literature was reviewed, surgical instrument collections were contacted, and the U.S. Patent and Trademark databases were queried to identify public patents and pre-granted applications of female inventors of handheld surgical instruments. Twenty-five female inventors were identified from published literature and 1551 unique females hold patents. This number pales when the denominator of male inventors is considered. Hence, to address the female surgeon's lack of instrumentation and design, there is a critical need for participatory ergonomics whereby both the female surgeon and engineer collaborate on design. [ABSTRACT FROM AUTHOR]

During severe septic shock and/or severe acute respiratory distress syndrome (ARDS) patients present with a limited cardio-ventilatory reserve (low cardiac output and blood pressure, low mixed venous saturation, increased lactate, low PaO2/FiO2 ratio, etc.), especially when elderly patients or co-morbidities are considered. Rescue therapies (low dose steroids, adding vasopressin to noradrenaline, proning, almitrine, NO, extracorporeal membrane oxygenation, etc.) are complex. Fever, above 38.5-39.5°C, increases both the ventilatory (high respiratory drive: large tidal volume, high respiratory rate) and the metabolic (increased O2 consumption) demands, further limiting the cardio-ventilatory reserve. Some data (case reports, uncontrolled trial, small randomized prospective trials) suggest that control of elevated body temperature (“fever control”) leading to normothermia (35.5-37°C) will lower both the ventilatory and metabolic demands: fever control should simplify critical care management when limited cardio-ventilatory reserve is at stake. Usually fever control is generated by a combination of general anesthesia (“analgo-sedation”, light total intravenous anesthesia), antipyretics and cooling. However general anesthesia suppresses spontaneous ventilation, making the management more complex. At variance, alpha-2 agonists (clonidine, dexmedetomidine) administered immediately following tracheal intubation and controlled mandatory ventilation, with prior optimization of volemia and atrio-ventricular conduction, will reduce metabolic demand and facilitate normothermia. Furthermore, after a rigorous control of systemic acidosis, alpha-2 agonists will allow for accelerated emergence without delirium, early spontaneous ventilation, improved cardiac output and micro-circulation, lowered vasopressor requirements and inflammation. Rigorous prospective randomized trials are needed in subsets of patients with a high fever and spiraling toward refractory septic shock and/or presenting with severe ARDS. [ABSTRACT FROM AUTHOR]

In the critical care setting, α-2 agonists present a multifaceted profile: sedation combined with arousability, suppression of delirium, preservation of respiratory drive, reduced O2 consumption, preserved renal function, and reduced protein metabolism. In addition, this review details the reduced arterial impedance, improved left ventricular performance, preserved vascular reactivity to exogenous amines, preserved cardiac baroreflex reactivity, preserved vasomotor baroreflex activity combined with a lowered pressure set point: these features may explain the good tolerance observed when α-2 agonists are used as continuous infusion without any loading dose. Reviewing the literature allows one to suggest that a new management appears possible with arousable sedation. However, it remains to be demonstrated whether this arousable sedation can be combined with the preservation of spontaneous ventilation, in the setting of severe respiratory distress, as opposed to conventional controlled mechanical ventilation combined with conventional sedation. Should such a speculative view be confirmed, then α-2 agonists will move from second-line sedative agents to first-line sedative agents. However, key studies are lacking to demonstrate the effect of α-2 agonists on physiological endpoints and outcome. Presently, the existing body of data suggests a niche for the use of α-2 agonists in the critical care setting. [ABSTRACT FROM PUBLISHER]

Background: In the post-operative setting, pressure lability is increased in hypertensive patients. α-2 agonists were shown qualitatively to reduce this lability qualitatively. Here, upon immobilization combined with emergence from anesthesia in rats and clonidine administration, pressure lability was quantitatively assessed and related to baroreflex sensitivity. Methods: After local anesthesia of all incisions and surgical wounds and myorelaxation with metocurine, rats had halothane withdrawn for 60 min. Rats received (a) saline ( n=8), (b) clonidine 30 μg/kg i.v ( n=8) simultaneous to halothane discontinuation and (c) halothane readministration ( n=8) 20 min after halothane discontinuation. Pressure lability was quantitatively assessed using occurrence/amplitude of peaks in systolic blood pressure (SBP) and cardiac baroreflex slope. Results: Clonidine was associated with partial blunting of hypertension, reduced standard deviation of SBP, reduced number and amplitude of peaks in systolic pressure. Clonidine was also associated with increased slope of the cardiac baroreflex upon early intervals of emergence, but not at later intervals. Conclusion: Clonidine reduces pressure lability upon immobilization stress combined to emergence from anesthesia, via parasympathetic activation and possibly sympathetic inhibition during early emergence as opposed to sympathetic inhibition during late emergence. [ABSTRACT FROM AUTHOR]

Progress over the last 50 years has led to a decline in mortality from ≈70% to ≈20% in the best series of patients with septic shock. Nevertheless, refractory septic shock still carries a mortality close to 100%. In the best series, the mortality appears related to multiple organ failure linked to comorbidities and/or an intense inflammatory response: shortening the period that the subject is exposed to circulatory instability may further lower mortality. Treatment aims at reestablishing circulation within a “central” compartment (i.e., brain, heart, and lung) but fails to reestablish a disorganized microcirculation or an adequate response to noradrenaline, the most widely used vasopressor. Indeed, steroids, nitric oxide synthase inhibitors, or donors have not achieved overwhelming acceptance in the setting of septic shock. Counterintuitively, α2-adrenoceptor agonists were shown to reduce noradrenaline requirements in two cases of human septic shock. This has been replicated in rat and sheep models of sepsis. In addition, some data show that α2-adrenoceptor agonists lead to an improvement in the microcirculation. Evidence-based documentation of the effects of alpha-2 agonists is needed in the setting of human septic shock. [ABSTRACT FROM AUTHOR]

Abstract: Alpha-2 adrenergic agonists (“alpha-2 agonists”) present multiple pharmacodynamic effects: rousable sedation, decreased incidence of delirium in the setting of critical care, preservation of respiratory drive, decreased whole body oxygen consumption, decreased systemic and pulmonary arterial impedance, improved left ventricular systolic and diastolic function, preserved vascular reactivity to exogenous catecholamines, preserved vasomotor baroreflex with lowered set point, preserved kidney function, decreased protein catabolism. These pharmacodynamic effects explain the interest for these drugs in the critical care setting. However, their exact role for sedation in critically ill-patients remains open for further studies. Given the few double-blind randomized multicentric trials available, the present non exhaustive analysis of the literature aims at presenting the utilization of alpha-2 agonists as potential first-line sedative agents, in the critical care setting. Suggestions regarding the use of alpha-2 agonists as sedatives are detailed. [Copyright &y& Elsevier]

Background: Pressure lability may be linked to the loss of the cardiac baroreflex. The reduction of the sensitivity of the cardiac baroreflex has not been delineated in the post-operative period according to age in normotensive patients. This study addresses pressure lability and slope of the cardiac baroreflex as a function of age. Methods: Patients were allocated to the following three groups: young (20–39 years, n=7), middle aged (40–59 years, n=7) and elderly (60–79 years, n=6), and studied before minor intra-abdominal surgery under CO2 peritoneal insufflation and nitrous oxide–isoflurane–sufentanil anesthesia, up to 24 h after extubation. An electrocardiogram and non-invasive beat-by-beat pressure monitoring (Finapres®) allowed offline calculation of the sensitivity of the cardiac baroreflex (‘sequence’ technique) and standard deviation (SD) of heart rate (HR; HR variability) and systolic blood pressure (SBP; pressure lability). Results: Before anesthesia, (a) an inverse relationship was observed between the slope of the cardiac baroreflex and age and (b) a trend ( P<0.09) existed between the slope of the cardiac baroreflex and pressure lability, irrespective of age. During the early post-operative period, young patients returned to their baseline slope of the cardiac baroreflex; no inverse relationship between increased SD of SBP and decreased SD of RR interval was observed. Middle-aged and elderly patients displayed a depressed slope of the cardiac baroreflex both before and after anesthesia. Conclusion: At variance with the pre-operative period, no simple inverse relationship was observed between increased pressure lability and depressed HR variability in young patients during the early post-operative period. [ABSTRACT FROM AUTHOR]

Intravenous B-type natriuretic peptide (BNP) enhances the bradycardia of reflexes from the heart, including the von Bezold-Jarisch reflex, but its site of action is unknown. The peptide is unlikely to penetrate the blood-brain barrier but could act on afferent or efferent reflex pathways. To investigate the latter, two types of experiment were performed on urethane-anesthetized (1.4 g/kg iv) rats. First, the activity was recorded extracellularly from single cardiac vagal motoneuroris (CVMs) in the nucleus ambiguus. CVMs were identified by antidromic activation from the cardiac vagal branch and by their barosensitivity. Phenyl biguanide (PBG), injected via the right atrium in bolus doses of 1–5 μg to evoke the von Bezold-Jarisch reflex, caused a dose-related increase in CVM activity and bradycardia. BNP infusion (25 pmol·kg-1min-1 iv) significantly enhanced both the CVM response to PBG (n = 5 rats) and the reflex bradycardia, but the log-linear relation between those two responses over a range of PBG doses was unchanged by BNP. The reflex bradycardia was not enhanced in five matched time-control rats receiving only vehicle infusions. In five other rats the cervical vagi were cut and the peripheral right vagus was stimulated supramaximally at frequencies of 1–20 Hz. The bradycardic responses to these stimuli were unchanged before, during, and after BNP infusion. We conclude that systemic BNP in a moderate dose enhances the von Bezold-Jarisch reflex activation of CVM, in parallel with the enhanced reflex bradycardia. That enhancement is due entirely to an action before the vagal efferent arm of the reflex pathway. [ABSTRACT FROM AUTHOR]

Abstract: The agro-environmental advantages of a good crop sequence system are widely recognised. Crop rotation is considered to be a cornerstone of ‘integrated farming’, particularly in view of its ability to maintain soil fertility and increase productivity. This paper focuses initially on the implementation of a crop sequence indicator (using a Geographic Information System allowing successive land parcel plans to be superimposed) developed using the Indigo method [Bockstaller, C., Girardin, P., 1996. The crop sequence indicator: a tool to evaluate crop rotations in relation to the requirements of integrated Arable Farming Systems. Aspects Appl. Biol. 47, 405–408] and it then discusses possible improvements and adaptations of this indicator to pedoclimatic conditions that differ from the original ones. An illustration of both these aspects is provided by the example of Wallonia in Belgium. The results were mapped for the whole Walloon region, allowing many common rotation types to be assessed from an agro-environmental perspective. A system enabling the regional authorities to monitor and, above all, to promote ways of managing crop sequences that are compatible with environmental protection is put forward for the Agricultural Areas concerned. [Copyright &y& Elsevier]

Extracellular recordings were made in the right nucleus ambiguus of urethane-anesthetized rats from 33 neurons that were activated at constant latency from the craniovagal cardiac branch. Their calculated conduction velocities were in the B-fiber range (1.6-13.8 m/s, median 4.2), and most (22/33) were silent. Active units were confirmed as cardiac vagal motoneurons (CVM) by the collision test for antidromic activation and by the presence of cardiac rhythmicity in their resting discharge (9/9). Brief arterial pressure rises of 20-50 mmHg increased the activity in five of five CVM by 0.1 ± 0.02 spikes·s[sup -1]·mmHg[sup -1] from a resting 3.8 ± 1.2 spikes/s; they also recruited activity in two of four previously silent cardiac branch-projecting neurons. CVM firing was modulated by the central respiratory cycle, showing peak activity during inspiration (8/8). Rat CVM thus show firing properties similar to those in other species, but their respiratory pattern is distinct. These findings are discussed in relation to mechanisms of respiratory sinus arrhythmia. [ABSTRACT FROM AUTHOR]

Presents information on a study documenting a rostral ventrolateral medulla (RVLM) catechol activation on systemic hydrogen load. Significant changes in mean arterial pressure among saline, intact and deafferented groups; Methodology used in the study; What the results indicate.

Presents a study which documented a rostral ventrolateral medulla (RVLM) catechol activation in rat rostral ventrolateral medulla after systemic isocapnic metabolic acidosis. Materials and methods used in conducting the study; Reference to the involvement of central catecholamines in cardiorespiratory coordination; Results and discussion on the study.

The authors describe the case of a 48-year-old man admitted to the critical care unit (CCU) who presented with septic shock and treated conventionally with volume loading and noradrenaline, and then again with clonidine infusion upon experiencing hypotension following a cholecystectomy. It is presumed that clonidine administered slowly lessens the release of endogenous NA. It is found that in hypertensive patients, clonidine decreases the dose of phenylephrine needed to increase systolic blood pressure.

OBJECTIVE: During septic shock, vasopressors are a cornerstone of therapy. In septic shock, very high doses of vasopressors sometimes have to be used due to vascular desensitization, the mechanisms of which are poorly understood. This study assesses whether [alpha]-2 agonists increase pressor responsiveness following lipopolysaccharide administration. DESIGN: Parallel groups of animals (n = 7 per group) subjected to pharmacologic interventions. SETTING: Physiology laboratory. SUBJECTS: Rats. INTERVENTIONS: In anesthetized rats, the pressor responses to increasing doses of norepinephrine (norepinephrine-systolic pressure curve) were assessed during a baseline period, after injection of saline or lipopolysaccharide, and after subsequent injection of saline, dexmedetomidine (100 [mu]g/kg IV), or clonidine (200 [mu]g/kg IV). MEASUREMENTS AND MAIN RESULTS: Differences in the slopes of the norepinephrine-pressure curves were assessed across drug treatments and intervals. The pressor dose of norepinephrine necessary to increase systolic pressure by 33 and 100 mm Hg (pressor dose 33 and pressor dose 100) was determined. Pressor responsiveness to norepinephrine decreased slightly over time in the saline-saline group (saline 1 or 2 vs baseline: mean decrease of the slope, 2 mm Hg/[mu]g/kg norepinephrine; p < 0.05), whereas there was a large decrease after lipopolysaccharide (lipopolysaccharide vs baseline: mean decrease of the slope, 7.2; p < 0.001). Clonidine alone had no effect, but when administered following lipopolysaccharide, it caused a striking increase in pressor responsiveness (mean slope after lipopolysaccharide, 10.7 [95% CI, 9.9-11.6]; after clonidine, 17.5 [95% CI, 16.7-18.4]). Similarly, dexmedetomidine administered after lipopolysaccharide caused a large increase in pressor responsiveness above lipopolysaccharide values. Accordingly the pressor dose 33 and pressor dose 100 values were lowered following lipopolysaccharide and restored by [alpha]-2 agonists. CONCLUSIONS: The pressor response to norepinephrine was reduced following lipopolysaccharide and increased to baseline levels following [alpha]-2 agonists. [ABSTRACT FROM AUTHOR]

Complexity analysis of short-term cardiovascular control is traditionally performed using entropy-based approaches including corrective terms or strategies to cope with the loss of reliability of conditional distributions with pattern length. This study proposes a new approach aiming at the estimation of conditional entropy (CE) from short data segments (about 250 samples) based on the k-nearest-neighbor technique. The main advantages are: (i) the control of the loss of reliability of the conditional distributions with the pattern length without introducing a priori information; (ii) the assessment of complexity indexes without fixing the pattern length to an arbitrary low value. The approach, referred to as k-nearest-neighbor conditional entropy (KNNCE), was contrasted with corrected approximate entropy (CApEn), sample entropy (SampEn) and corrected CE (CCE), being the most frequently exploited approaches for entropy-based complexity analysis of short cardiovascular series. Complexity indexes were evaluated during the selective pharmacological blockade of the vagal and/or sympathetic branches of the autonomic nervous system. We found that KNNCE was more powerful than CCE in detecting the decrease of complexity of heart period variability imposed by double autonomic blockade. In addition, KNNCE provides indexes indistinguishable from those derived from CApEn and SampEn. Since this result was obtained without using strategies to correct the CE estimate and without fixing the embedding dimension to an arbitrary low value, KNNCE is potentially more valuable than CCE, CApEn and SampEn when the number of past samples most useful to reduce the uncertainty of future behaviors is high and/or variable among conditions and/or groups. [ABSTRACT FROM AUTHOR]

Abstract: A juxtaposition of long and short RR intervals was observed in 2 hypertensive patients recovering from major surgery under spontaneous ventilation. Sinus rhythm was ascertained throughout the recording. These oscillations could not be linked one-to-one to ventilatory cycles. [Copyright &y& Elsevier]