16,346 research outputs found

    Hominid butchers and biting crocodiles in the African Plio-Pleistocene.

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    Zooarchaeologists have long relied on linear traces and pits found on the surfaces of ancient bones to infer ancient hominid behaviors such as slicing, chopping, and percussive actions during butchery of mammal carcasses. However, such claims about Plio-Pleistocene hominids rely mostly on very small assemblages of bony remains. Furthermore, recent experiments on trampling animals and biting crocodiles have shown each to be capable of producing mimics of such marks. This equifinality-the creation of similar products by different processes-makes deciphering early archaeological bone assemblages difficult. Bone modifications among Ethiopian Plio-Pleistocene hominid and faunal remains at Asa Issie, Maka, Hadar, and Bouri were reassessed in light of these findings. The results show that crocodiles were important modifiers of these bone assemblages. The relative roles of hominids, mammalian carnivores, and crocodiles in the formation of Oldowan zooarchaeological assemblages will only be accurately revealed by better bounding equifinality. Critical analysis within a consilience-based approach is identified as the pathway forward. More experimental studies and increased archaeological fieldwork aimed at generating adequate samples are now required

    The Size and Shape of Local Voids

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    We study the size and shape of low density regions in the local universe which we identify in the smoothed density field of the PSCz flux limited IRAS galaxy catalogue. After quantifying the systematic biases that enter in the detection of voids using our data set and method, we identify, using a smoothing length of 5 h1h^{-1} Mpc, 14 voids within 80 h1h^{-1} Mpc and using a smoothing length of 10 h1h^{-1} Mpc, 8 voids within 130 h1h^{-1} Mpc. We study the void size distribution and morphologies and find that there is roughly an equal number of prolate and oblate-like spheroidal voids. We compare the measured PSCz void shape and size distributions with those expected in six different CDM models and find that only the size distribution can discriminate between models. The models preferred by the PSCz data are those with intermediate values of σ8(0.83)\sigma_{8} (\simeq 0.83), independent of cosmology.Comment: final version, Accepted in MNRA

    Identification of direct residue contacts in protein-protein interaction by message passing

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    Understanding the molecular determinants of specificity in protein-protein interaction is an outstanding challenge of postgenome biology. The availability of large protein databases generated from sequences of hundreds of bacterial genomes enables various statistical approaches to this problem. In this context covariance-based methods have been used to identify correlation between amino acid positions in interacting proteins. However, these methods have an important shortcoming, in that they cannot distinguish between directly and indirectly correlated residues. We developed a method that combines covariance analysis with global inference analysis, adopted from use in statistical physics. Applied to a set of >2,500 representatives of the bacterial two-component signal transduction system, the combination of covariance with global inference successfully and robustly identified residue pairs that are proximal in space without resorting to ad hoc tuning parameters, both for heterointeractions between sensor kinase (SK) and response regulator (RR) proteins and for homointeractions between RR proteins. The spectacular success of this approach illustrates the effectiveness of the global inference approach in identifying direct interaction based on sequence information alone. We expect this method to be applicable soon to interaction surfaces between proteins present in only 1 copy per genome as the number of sequenced genomes continues to expand. Use of this method could significantly increase the potential targets for therapeutic intervention, shed light on the mechanism of protein-protein interaction, and establish the foundation for the accurate prediction of interacting protein partners.Comment: Supplementary information available on http://www.pnas.org/content/106/1/67.abstrac

    The effectiveness of interventions to improve the care and management of people with dementia in general hospitals: a systematic review

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    Background: People with dementia are at greater risk of being admitted to hospital where care may not be tailored to their needs. Interventions improving care and management are vital. Aim: Assess the effectiveness of interventions designed to improve the care and management of people with dementia in hospital. Method: Six medical and trial registry, and grey literature databases were searched (1999‐1998/2018). Search terms included “Dementia,” “Hospital,” and “Intervention” and limited to experimental designs. Interventions designed to improve the care and management of people with dementia in the general hospital setting were examined. Outcomes included behavioural and psychological symptoms of dementia (BPSD), psychosocial, clinical, staff knowledge, and length of hospital stay. The CASP tools, Cochrane risk of bias tool, and GRADE system assessed methodological quality and certainty of evidence. Results: 9003 unique citations were identified; 24 studies were included. Studies were limited in study design and their conduct was at a risk of bias. There is very low‐quality evidence that multisensory behaviour therapy reduces BPSD. There is low‐quality evidence that a multidisciplinary programme reduces postoperative complications and that robot‐assisted therapy, music therapy, multimodal‐comprehensive care, person‐centred care, and family‐centred function‐focused care interventions improved staff knowledge, competence, efficacy, and communication. No studies reported reduced length of stay. Conclusions: Whilst we found that these interventions improved the care and management of people with dementia in hospital, it was low‐ to very low‐quality evidence. New clinical recommendations cannot be made based on current evidence, and robust trial designs are necessary to inform evidence‐based care

    Farmer perspectives on administrative burdens and potential compensation structures: A short summary report of farmer interviews from spring 2022. Vermont Payment for Ecosystem Services Technical Research Report # 3c

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    Interviews with 35 Vermont farmers explored their perspectives on compensation associated with a soil health payment for ecosystem services (PES) program in 2022. This report summarizes thematic analysis of those interviews. Farmers’ willingness to participate in a soil health PES is linked to both the burden of enrollment paperwork and the payment level, among other factors. If deciding whether to participate in a soil health PES program, nearly all farmers said they would weigh the time and energy put into the administrative workload against the perceived benefits and value of the program, i.e., the payment level or technical assistance provided. Farmers appreciate straightforward program applications and paperwork that are aligned with their interests and schedules. Understandable language and access to technical assistance is also important to farmers when applying to programs and/or handling paperwork. A PES program should be as straightforward as possible to ease administrative burdens. At a minimum, compensation should reflect the paperwork and engagement burden for farmers. 100% of the farmers we interviewed highly valued soil health on their farms. Most farmers liked the idea of a PES program which compensates them for soils with good health. They appreciated how a program could enable and/or incentive them to maintain or improve soil health on their farms. Farmers identified the importance for a soil health program to consider differences between farms and soils when setting reasonable performance expectations and payment rates. Farmers expressed a wide variety of different perspectives and preferences about what payment rates would be meaningful to them in a PES program. There did not seem to be a ‘one-size-fits- all’ level of payment, and associating payment levels with soil health metrics proved challenging for some farmers. While many farmers were able to provide estimates of the level of payment they would be willing to accept, some were either unwilling or unable to determine appropriate levels of payment based on soil health metrics. Most farmers thought about the investment of time and resources needed when thinking about payment rates. Overall, the average level of payment that would be meaningful at the whole farm level described by interviewees was $9,322.00 per farm. However, significant differences in payment levels were detected by farm acreage. Farmers with fewer acres tended to require higher per acre payment rates than farmers with more acres. Conversely, farmers with larger acreage tended to require higher total payment. Approximately 90% of farmers interviewed were supportive of per acre payments in a soil health PES program. Nearly 50% of interviewees expressed concerns about how undifferentiated per acre payment rates across different farm types would favor the participation of farms with more acres and those which were less intensively managed. The potential value of a soil health PES program was widely recognized to be more than just monetary. Farmers expressed interest in both the monetary and non-monetary benefits that a potential program might offer them. Most were interested in the program providing some combination of financial payments, access to farm-specific data, connection to a farmer network/learning community, and technical assistance
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