The neuropsychological correlates of individuals at risk for bipolar I disorder

Bipolar disorder is now recognized as a severe psychiatric disorder characterized by extreme mood swings and cognitive deficits, most notably in the domains of verbal learning, executive function, and sustained attention. Neurocognitive deficits have been proposed as vulnerability markers or endophenotypes for the development of bipolar disorder. However, few research studies have examined whether neurocognitive deficits also exist in individuals at risk for bipolar disorder or first-degree relatives. This study examined neurocognitive function in individuals with bipolar disorder, their first-degree relatives, and a normal control group. Results indicated that individuals with bipolar disorder and their unaffected relatives demonstrated neuropsychological deficits in comparison to the normal control group in the domains of visuospatial/constructional abilities, executive function, and visual learning and memory. In general, the unaffected relatives demonstrated an intermediate level of performance in comparison to the normal control and bipolar group. After adjustment for mood symptomotology, significant differences remained only in the visuospatial/constructional and executive function domains. Individuals with bipolar disorder also demonstrated a differential right versus left hemisphere deficit with respect to neurocognitive tasks, providing support for the theory of right hemisphere dysfunction in bipolar affective disorder. Deficits on specific neuropsychological tests, most notably Digit Symbol, Block Design, and Judgment of Line Orientation may be indicative of cognitive endophenotypes for bipolar disorder. Replication studies are needed to identify these deficits as neurocognitive phenotypes and to further examine hemispheric functioning in bipolar affective disorder

The role of attributional style, dysfunctional attitudes, and negative life events on depression in college students

Two major cognitive theories, Beck\u27s cognitive theory (1967) and Seligman\u27s reformulated learned helplessness theory (1978), have dominated depression research over the last fifteen years. Both of these theories propose a diathesis-stress model in which significant life events are imparted by specific cognitive styles; This study incorporated the major tenets of both theories to examine the role of dysfunctional attitudes, attributional style, and negative life events on Beck Depression Inventory scores in college students. It was hypothesized that the latter two components would interact with negative life events to predict initial and future depression scores; Ninety-eight introductory psychology students completed a series of questionnaires at four separate time periods. Trends were obtained for both attributional style and dysfunctional attitudes to interact with negative events to predict initial depression scores. Significant interactions were obtained in all three prospective time periods. The findings of this investigation lend support to both Beck\u27s cognitive theory and Seligman\u27s reformulated learned helplessness theory

Drainage of sandplain seeps for salinity control and stock water supplies

Sandplain seeps are derived from a shallow groundwater system which flows from the deep sandplain soils upslope. Seeps result in small areas of salinity and waterlogging, which can be the focus of soil erosion. Sandplain seeps may represent as much as 10 per cent of Western Australia\u27s salt problem in the drier agricultural area. Several drainage experiments conducted between 1986 and 1989 determined the best methods of reclaiming sandplain seeps. This article discusses the results of these drainage experiments. It comments on the most suitable method for reclaiming sandplain seeps and developing them for stock water supplies

Preliminary groundwater and salinity investigations in the eastern wheatbelt. 3. Welbungin and Beacon River catchments

Water-tables show no obvious signs of a nett annual rise in the bores monitored in the valley floor, lower slope areas over the three year period. Groundwaters are extremely saline, the sedimentary and saprolite aquifers permeable (hydraulic conductivity range 0.1-2.0 m/day) (0.0001). Future management systems should seek to decrease recharge by changing rotations and farm practises while increasing discharge by using trees, pumps and halophytes. Options are available for drainage

Preliminary groundwater and salinity investigation in the eastern wheatbelt. 1. Brennand\u27s Catchment

Groundwaters were found to be 10 m below the floor of the ancestral playa lake in Brennand\u27s catchment. They were extremely saline. A groundwater flow system was not established on much of the catchment. Flow was observed to be occurring from recharge areas near the playa lakes towards the midslopes of the catchment. Flow was apparently restricted from leaving Brennand\u27s catchment because of obstruction to groundwaters created by dolerite dykes

Preliminary groundwater and salinity investigations in the eastern wheatbelt 2. Merredin catchment

Saline groundwater occurs within twelve metres of the surface throughout the valley of the Merredin catchment. Saline groundwater occurs within deep sediments deposited in the valley and deeply-weathered bedrock materials. Rapid groundwater recharge appears to be taking place in sandy-textured soils high in the landscape and directly into the Cainozoic sediments in the valley floor. Water-tables are rising at approximately ten centimetres each year in the upper catchment area

Field Resistance to Black Root Rot of Soybean and Response of Selected Cultivars to Cylindrocladium Crotalariae Inoculum Density.

Soybean cultivars were evaluated during two consecutive years for field resistance to black root rot (BRR) caused by Cylindrocladium crotalariae. Evaluations were conducted in a naturally infested field with a 2-year history of BRR incidence. Densities of microsclerotia (ms) were measured at planting by a soil elutriation technique. Disease classes were based on a 0-4 scale of foliage symptoms (0 = no symptoms, 4 = 76-100 percent of leaves per plant displaying symptoms). Chronological age and physiological stage of plants were compared in the determination of disease indices. Significant (P = 0.05) differences in disease index values were detected among the cultivars for both years. Cultivars \u27Dare\u27, \u27Davis\u27, \u27Forrest\u27, \u27Lancer\u27, \u27Lee 74\u27, and \u27Hood 75\u27 exhibited the greatest degree of field resistance for both years, whereas \u27Bossier\u27, \u27Centennial\u27, and \u27McNair 600\u27 were the most susceptible. In greenhouse experiments, cultivars \u27Bossier\u27, \u27Cobb\u27, and \u27Hood 75\u27 were grown to maturity in field soil (Olivier silt loam, pH 6.0) which had been artificially infested with ms of C. crotalariae. Five-day-old seedlings were planted in 20-cm plastic-lined pots containing a soil:vermiculite mixture (1:1, v/v) with adjusted inoculum densities of 0.005, 0.05, 0.5, 5.0, and 50.0 ms/g of soil (dry weight basis). Measurements of plant growth, yield, mortality, root rot severity, and rate of fungus recovery from taproots were recorded at maturity. \u27Bossier\u27 and \u27Cobb\u27 sustained significant (P = 0.05) reductions in growth and yield at (GREATERTHEQ) 0.5 ms/g of soil; \u27Hood 75\u27 sustained likewise at (GREATERTHEQ) 5.0 ms/g of soil

The structure of the SufS–SufE complex reveals interactions driving protected persulfide transfer in iron-sulfur cluster biogenesis

Fe-S clusters are critical cofactors for redox chemistry in all organisms. The cysteine desulfurase, SufS, provides sulfur in the SUF Fe-S cluster bioassembly pathway. SufS is a dimeric, pyridoxal 5\u27-phosphate-dependent enzyme that uses cysteine as a substrate to generate alanine and a covalent persulfide on an active site cysteine residue. SufS enzymes are activated by an accessory transpersulfurase protein, either SufE or SufU depending on the organism, which accepts the persulfide product and delivers it to downstream partners for Fe-S assembly. Here, using Escherichia coli proteins, we present the first X-ray crystal structure of a SufS/SufE complex. There is a 1:1 stoichiometry with each monomeric unit of the EcSufS dimer bound to one EcSufE subunit, though one EcSufE is rotated ∼7° closer to the EcSufS active site. EcSufE makes clear interactions with the α16 helix of EcSufS and site-directed mutants of several α16 residues were deficient in EcSufE binding. Analysis of the EcSufE structure showed a loss of electron density at the EcSufS/EcSufE interface for a flexible loop containing the highly conserved residue R119. An R119A EcSufE variant binds EcSufS but is not active in cysteine desulfurase assays and fails to support Fe-S cluster bioassembly in vivo. 35S-transfer assays suggest that R119A EcSufE can receive a persulfide, suggesting the residue may function in a release mechanism. The structure of the EcSufS/EcSufE complex allows for comparison with other cysteine desulfurases to understand mechanisms of protected persulfide transfer across protein interfaces