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A family of ferrocenyl amino alcohols (14 examples) has been prepared from the corresponding planar chiral ketones and evaluated as a new class of chiral ligands for asymmetric ethyl‐ and phenylzinc additions to aldehydes. The highly enantioselective synthesis of these ligands is facile, scalable, robust and relies on the use of cheaply available starting materials. Asymmetric ethyl additions proceeded smoothly at ambient temperature, with reaction times as short as 1 hour furnishing the desired products in up to 90 % yield and 99 % ee. The corresponding phenyl additions afforded products in up to 81 % yield and 88 % ee. The observed stereochemical outcome for the addition of diethylzinc was rationalized and the key proposed transition state was supported by an analysis of the X‐ray structures of a series of amino alcohol ligands. [ABSTRACT FROM AUTHOR]

Diol scaffolds have been utilized as highly effective catalysts and ligands in a wide range of catalytic asymmetric transformations. For scaffolds to be successful as broadly used motifs, they should be prepared cheaply through facile routes and be easily handled. Herein, the synthesis of a family of planar chiral diols based on a modular and robust three‐step route is described, which yields catalytically active diols in >99 % de and >99 % ee, with up to seven different chiral elements. These diols have been characterized by X‐ray crystallographic analysis, which provides clear evidence for the likely transition state when applied in the asymmetric hetero‐Diels‐Alder reaction. Without altering the stereochemistry of the catalyst backbone, it is possible to access both enantiomers of the product by varying the substitution of the catalyst at the α‐position. [ABSTRACT FROM AUTHOR]

Background: Sex is an important biological variable which can influence the prevalence, clinical presentation, and progression of neurodegenerative diseases. Little is known regarding possible sex differences in prodromal dementia with Lewy bodies (DLB). Method: We analyzed data from the National Alzheimer's Coordinating Center's Uniform Data Set (NACC database is funded by NIH U01‐AG016976). Annual visits occurred across 39 past/present Alzheimer's Disease Research Centers (ADRC) between September 2005 and September 2021. We included non‐demented participants at baseline who were clinically diagnosed with DLB by ADRC staff at a subsequent visit. The presence of motor symptoms, visual hallucinations, REM sleep behavior disorder (RBD), cognitive fluctuations, and neuropsychiatric symptoms were assessed through clinical exam and informant responses 1–2 years prior to DLB diagnosis. Result: We identified 160 participants with DLB (82.5% male). Male and female groups differed in age and ethnicity (Table 1).There were no differences in education, cognition, functional status, severity of neuropsychiatric symptoms, or number of visits prior to phenoconversion to DLB. RBD was more prevalent in men (58‐62% vs. 25–36% women). Cognitive fluctuations were also more common among men (33‐40% vs. 6–18% women). Men reported a higher prevalence of visual hallucinations 2‐years prior to dementia diagnosis (23% vs. 6% women), but visual hallucinations were more prevalent in women than men at the first visit with dementia diagnosis (54% women vs. 43% men). Motor slowing and parkinsonian gait were prevalent among both groups; however, tremor and rigidity were more common in men, while postural instability and falls were more frequent in women. Apathy was common in both groups; however, anxiety was more frequent in men, and women had a higher prevalence of depression. (Table 2). The groups did not differ in rates of 1 vs. 2+ core clinical features 1‐year prior to diagnosis (Table 3). Conclusion: This descriptive analysis appears to indicate there are sex differences in the prodromal presentation of DLB. Men may present with established core features earlier than women. Limitations include lack of pathological confirmation and the number of female and ethno‐racially diverse participants. Understanding differences in clinical presentations may inform diagnostic criteria and therefore improve clinical sensitivity. [ABSTRACT FROM AUTHOR]

Meditation has been studied as a way of reducing stress in counseling clients since the 1960s. Alcoholics Anonymous, Narcotics Anonymous, and new wave behavior therapies incorporate meditation techniques in their programs. This article identifies meditation's curative factors and limitations when using medita- tion in addiction settings. [ABSTRACT FROM AUTHOR]

The effects of metals and petroleum hydrocarbons on benthic marine diatom communities were assessed using a manipulative field experiment at Casey Station, Antarctica. Uncontaminated, metal contaminated, and petroleum hydrocarbon contaminated sediments were deployed for 11 weeks during the 1999 austral summer. The treatments were deployed at three different locations: Brown Bay, which has elevated levels of anthropogenic contaminants, and two uncontaminated reference locations, O'Brien Bay and Sparkes Bay, the latter of which has naturally occurring high concentrations of some heavy metals. At each location, significant differences between the composition of diatom communities recruiting to control and petroleum hydrocarbon contaminated treatments were observed. Navicula directa (Smith) Ralfs occurred at lower abundances in the petroleum hydrocarbon contaminated treatments than in the control treatments. In contrast, Navicula cancellata Donkin occurred at higher relative abundances in both contaminated treatments relative to the control treatment. Interactions between treatment and location were also observed for several species, including Navicula glaciei Van Heurck. Significant differences in the overall community composition of diatom communities between control and metal contaminated treatments and metal contaminated and petroleum hydrocarbon contaminated treatments were only observed within Brown Bay. The location of deployment also had a significant influence on the composition of diatom communities. Brown Bay had higher abundances of Achnanthes brevipes Agardh but lower abundances of Navicula aff. cincta (Ehrenberg) Van Heurck than either reference locations. This experiment demonstrated that benthic diatom communities are sensitive to sediment contamination and would be suitable for future monitoring work within this and other areas of Antarctica. [ABSTRACT FROM AUTHOR]

The effects of metals and petroleum hydrocarbons on benthic marine diatom communities were assessed using a manipulative field experiment at Casey Station, Antarctica. Uncontaminated, metal contaminated, and petroleum hydrocarbon contaminated sediments were deployed for 11 weeks during the 1999 austral summer. The treatments were deployed at three different locations: Brown Bay, which has elevated levels of anthropogenic contaminants, and two uncontaminated reference locations, O'Brien Bay and Sparkes Bay, the latter of which has naturally occurring high concentrations of some heavy metals. At each location, significant differences between the composition of diatom communities recruiting to control and petroleum hydrocarbon contaminated treatments were observed. Navicula directa (Smith) Ralfs occurred at lower abundances in the petroleum hydrocarbon contaminated treatments than in the control treatments. In contrast, Navicula cancellata Donkin occurred at higher relative abundances in both contaminated treatments relative to the control treatment. Interactions between treatment and location were also observed for several species, including Navicula glaciei Van Heurck. Significant differences in the overall community composition of diatom communities between control and metal contaminated treatments and metal contaminated and petroleum hydrocarbon contaminated treatments were only observed within Brown Bay. The location of deployment also had a significant influence on the composition of diatom communities. Brown Bay had higher abundances of Achnanthes brevipes Agardh but lower abundances of Navicula aff. cincta (Ehrenberg) Van Heurck than either reference locations. This experiment demonstrated that benthic diatom communities are sensitive to sediment contamination and would be suitable for future monitoring work within this and other areas of Antarctica. [ABSTRACT FROM AUTHOR]

The effects of climatic variables on lake-water total organic carbon (TOC) concentrations and benthic and pelagic primary producers during the past 45 yr were assessed using the sediment records of two subarctic lakes, one with mires and one without mires connected to the lake. The lake with a mire showed large and synchronous changes in the planktonic to benthic (P : B) ratio of diatoms and concentrations of TOC inferred from nearinfrared spectroscopy. During periods of warm temperatures, high precipitation, and long ice-free conditions, we inferred high TOC in the lake, and the diatom community was dominated by planktonic species. The stable carbon isotopic (δ13C) values of sediment organic matter were negatively correlated with inferred TOC concentration and P :B ratio. We suggest that the changes in TOC and P : B ratio were a result of changing climate, permafrost degradation, and related changes in the catchment. Terrestrial organic matter, by its strong effect on the penetration of light through the lake water, possibly affected the habitats available for benthic photosynthesis and thus the d13C of the sediment organic matter. The large changes in recent times may also be because of unusually long ice-free periods, warmer temperatures, and other associated limnological changes. The lake with no mire next to the lake showed only minor changes in lake-water TOC during the same period and P :B ratio remained almost constant until the past 5 yr, when the P :B ratio increased rapidly. The observed changes in P :B ratio within this lake may be because of complex interactions of several climate-related variables. [ABSTRACT FROM AUTHOR]