腕间的钻石贵族

自古以来,钻石对每个人来说都是一个梦,一个理想和一种,形象。然而,不少表迷认为钻石表没有机械表的精密性和复杂性,感觉较为女性化。其实,钻石表比任何复杂机械表更有趣,因为不同钻石会散发出不同的天然荧光度;还有一个重要元素。就是由于钻石本身的稀缺性,镶嵌有钻石的腕表更能保值。     

Nitrogen and potassium fertilizer vs. nematode and weevil effects on yield and foliar nutrient status of banana in Uganda

Banana (Musa AAA) production is declining in central Uganda. A decline in soil fertility is often cited as one of the causes of the declining production. From 1996 to 1998, we studied banana yield responses to N and K fertilization at three sites in Uganda, where plantations ranged in age from 8 to 50 years. Phosphorus was applied to all treatments at 25 kg ha⁻¹, while N and K were applied (kg ha⁻¹) at 0N-0K, 0N-100K, 100N-0K, 100N-100K, and 100N-200K. Fresh fruit yields ranged from 4 to 67 Mg ha⁻¹ yr⁻¹. At one site the yield response to 100N-100K fertilization was significant (p < 0.01). The other sites showed positive but non-significant yield responses to N or NK fertilization. Economic analysis indicated that fertilizer use would be profitable only at the single site with significant yield increases. This site had negligible banana weevil (Cosmopolites sordidus (Germar)) and nematode (Radopholus similis; Helicotylenchus multicinctus) populations whereas the other sites were characterized by either severe nematode or weevil pressure. Fertilizer did not affect the damage caused by either nematodes or weevils. The best predictor of yield (p< 0.001, r ² = 0.75) was the number of functional leaves during anthesis. Measured soil nutrient parameters were highly variable but fell within sufficiency ranges. Foliar N contents were near diagnostic norms, but K levels fell below them, even when yields were satisfactory, suggesting that norms developed from other regions may not be suitable for Uganda. We conclude that in established plantations soil nutrient status is but one, and often a secondary, factor in the decline of banana yields in the central region of Uganda. Pest and disease infestations that result in reduced plantation productivity will need to be addressed before fertilizer use is likely to make a significant improvement in banana fruit yields. This revised version was published online in June 2006 with corrections to the Cover Date.     

Predicting the impact of child sexual abuse on women: The role of abuse severity, parental support, and coping strategies.

Female Navy recruits (N=5,226) completed surveys assessing history of childhood sexual abuse (CSA), childhood strategies for coping with CSA, childhood parental support, and current psychological adjustment. Both CSA and parental support independently predicted later adjustment. In analyses examining whether CSA victims' functioning was associated with CSA severity (indexed by 5 variables), parental support (indexed by 3 variables), and coping (constructive, self-destructive, and avoidant), the negative coping variables were the strongest predictors. A structural equation model revealed that the effect of abuse severity on later functioning was partially mediated by coping strategies. However, contrary to predictions, the model revealed that childhood parental support had little direct or indirect impact on adult adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using the continuous quality improvement process to safely lower the cesarean section rate

BACKGROUND: In 1994 a five-year prospective observational study (including 38,541 singleton live-born deliveries) based on maternal and neonatal hospital administrative discharge data for DRGs 370-375 was launched at Cedars Sinai Medical Center (CSMC) in Los Angeles. In 1993 a cesarean section (C-section) reduction task force was first convened and several interventions were conducted and monitored during a two-year period. In 1995 CSMC joined the Institute for Healthcare Improvement's (IHI's) national collaborative on lowering C-section rates. RESULTS: The first intervention involved physician education (grand rounds) and occurred during the preintervention baseline period. Providing physician-specific data had been implemented before participation in the IHI collaborative. Two other interventions were implemented before the collaborative versus 13 interventions after. The C-section rate decreased from 26.0% in the baseline period in 1993 to 20.5% in 1997, a 21.2% reduction. During the postintervention period, the C-section rate increased to 23.5%. There was no statistically or clinically significant increase in clavicular fractures, brachial plexus injuries, or cerebral hemorrhage in the four study years, compared to the baseline period. DISCUSSION: It is possible to safely reduce C-section delivery rates. Activities are now under way to involve additional private physician leaders in the continuous quality improvement effort. Although the small increase in the C-section rate during the postintervention period may represent statistical variation, and in itself may not be clinically significant, it supports the thesis that ongoing, continuous organizational support is required to achieve and maintain gains.     

A comparison of rCBF patterns during letter and semantic fluency.

To evaluate the functional neuroanatomies underlying letter and category fluency, 18 normal controls were studied with oxygen-15 water regional cerebral blood flow positron emission tomography. Three counterbalanced conditions each consisted of 6 trials (45 s each): letter fluency (generating words when cued with a particular letter), semantic fluency (generating words when cued with a particular category), and a control condition (generating days of the week and months of the year). Relative to the control, participants activated similar brain regions during both fluency tasks, including the anterior cingulate, left prefrontal regions, thalamus, and cerebellum; reductions were found in parietal and temporal regions. In a direct comparison of the 2 fluency tasks, inferior frontal cortex and temporoparietal cortex (hypothesized to participate in a phonologic loop for accessing word pronunciation) were activated more during letter than semantic fluency, whereas left temporal cortex (associated with access to semantic storage) was activated more during semantic than letter fluency. This study identifies subtle differences in the neural networks underlying letter and semantic fluency that may underlie the dissociation of these abilities in patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

About this issue: Diversity and convergence in the study of psychological trauma.

In this editorial, the editor discusses the diversity of material in the current issue of Psychological Trauma: Theory, Research, Practice and Policy (PT: TRPP). He addresses questions that were raised by the pieces in this issue including ones as fundamental as what constitutes a psychological trauma. The editors believe that it is extremely important that as many facets of this terrain be examined and represented in the pages of PT: TRPP as possible. Only by continually and actively striving to maintain an inclusive perspective can we hope to work toward evolving a reasonable level of understanding of psychological trauma in all its richness and complexity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delayed diagnosis of acute rheumatic fever in adults: a forgotten cause of febrile polyarthritis

Acute rheumatic fever is a nonsuppurative sequela of upper respiratory tract infection with group A streptococci. We describe our recent experience with the diagnosis and management of 3 cases of acute rheumatic fever to highlight the delays that may arise in the diagnosis of this condition. In adults, febrile polyarthritis is the most common presentation of acute rheumatic fever. Increased awareness on the part of the physician is necessary to ensure both prompt and accurate diagnosis of this cause of febrile polyarthritis.     

Lidocaine toxicity in primary afferent neurons from the rat

Evidence from both clinical studies and animal models suggests that the local anesthetic, lidocaine, is neurotoxic. However, the mechanism of lidocaine-induced toxicity is unknown. To test the hypothesis that toxicity results from a direct action of lidocaine on sensory neurons we performed in vitro histological, electrophysiological and fluorometrical experiments on isolated dorsal root ganglion (DRG) neurons from the adult rat. We observed lidocaine-induced neuronal death after a 4-min exposure of DRG neurons to lidocaine concentrations as low as 30 mM. Consistent with an excitotoxic mechanism of neurotoxicity, lidocaine depolarized DRG neurons at concentrations that induced cell death (EC50 = 14 mM). This depolarization occurred even though voltage-gated sodium currents and action potentials were blocked effectively at much lower concentrations. (EC50 values for lidocaine-induced block of tetrodotoxin-sensitive and -resistant voltage-gated sodium currents were 41 and 101 microM, respectively.) At concentrations similar to those that induced neurotoxicity and depolarization, lidocaine also induced an increase in the concentration of intracellular Ca++ ions ([Ca++]i; EC50 = 21 mM) via Ca++ influx through the plasma membrane as well as release of Ca++ from intracellular stores. Finally, lidocaine-induced neurotoxicity was attenuated significantly when lidocaine was applied in the presence of nominally Ca(++)-free bath solution to DRG neurons preloaded with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Our results indicate: 1) that lidocaine is neurotoxic to sensory neurons; 2) that toxicity results from a direct action on sensory neurons; and 3) that a lidocaine-induced increase in intracellular Ca++ is a mechanism of lidocaine-induced neuronal toxicity.