- Proceedings of the National Academy of Sciences of the United States of America
- Published over 7 years ago
The Acheulean technological tradition, characterized by a large (>10 cm) flake-based component, represents a significant technological advance over the Oldowan. Although stone tool assemblages attributed to the Acheulean have been reported from as early as circa 1.6-1.75 Ma, the characteristics of these earliest occurrences and comparisons with later assemblages have not been reported in detail. Here, we provide a newly established chronometric calibration for the Acheulean assemblages of the Konso Formation, southern Ethiopia, which span the time period ∼1.75 to <1.0 Ma. The earliest Konso Acheulean is chronologically indistinguishable from the assemblage recently published as the world's earliest with an age of ∼1.75 Ma at Kokiselei, west of Lake Turkana, Kenya. This Konso assemblage is characterized by a combination of large picks and crude bifaces/unifaces made predominantly on large flake blanks. An increase in the number of flake scars was observed within the Konso Formation handaxe assemblages through time, but this was less so with picks. The Konso evidence suggests that both picks and handaxes were essential components of the Acheulean from its initial stages and that the two probably differed in function. The temporal refinement seen, especially in the handaxe forms at Konso, implies enhanced function through time, perhaps in processing carcasses with long and stable cutting edges. The documentation of the earliest Acheulean at ∼1.75 Ma in both northern Kenya and southern Ethiopia suggests that behavioral novelties were being established in a regional scale at that time, paralleling the emergence of Homo erectus-like hominid morphology.
Photosynthetic starch reserves that accumulate in Arabidopsis leaves during the day decrease approximately linearly with time at night to support metabolism and growth. We find that the rate of decrease is adjusted to accommodate variation in the time of onset of darkness and starch content, such that reserves last almost precisely until dawn. Generation of these dynamics therefore requires an arithmetic division computation between the starch content and expected time to dawn. We introduce two novel chemical kinetic models capable of implementing analog arithmetic division. Predictions from the models are successfully tested in plants perturbed by a night-time light period or by mutations in starch degradation pathways. Our experiments indicate which components of the starch degradation apparatus may be important for appropriate arithmetic division. Our results are potentially relevant for any biological system dependent on a food reserve for survival over a predictable time period. DOI:http://dx.doi.org/10.7554/eLife.00669.001.
- Journal of the American Medical Informatics Association : JAMIA
- Published over 7 years ago
Adverse drug events cause substantial morbidity and mortality and are often discovered after a drug comes to market. We hypothesized that Internet users may provide early clues about adverse drug events via their online information-seeking. We conducted a large-scale study of Web search log data gathered during 2010. We pay particular attention to the specific drug pairing of paroxetine and pravastatin, whose interaction was reported to cause hyperglycemia after the time period of the online logs used in the analysis. We also examine sets of drug pairs known to be associated with hyperglycemia and those not associated with hyperglycemia. We find that anonymized signals on drug interactions can be mined from search logs. Compared to analyses of other sources such as electronic health records (EHR), logs are inexpensive to collect and mine. The results demonstrate that logs of the search activities of populations of computer users can contribute to drug safety surveillance.
People often fail to muster the motivation needed to initiate goal pursuit. Across five laboratory experiments, we explored occasions when people naturally experience enhanced motivation to take actions that facilitate goal pursuit and why certain dates are more likely to spur goal initiation than others. We present causal evidence that emphasizing a temporal landmark denoting the beginning of a new time period increases people’s intentions to initiate goal pursuit. In addition, we propose and show that people’s strengthened motivation to begin pursuing their aspirations following such temporal landmarks originates in part from the psychological disassociation these landmarks induce from a person’s past, imperfect self.
- Journal of strength and conditioning research / National Strength & Conditioning Association
- Published over 7 years ago
The purpose of this study was to compare the distances covered during a 11-a-side soccer match after players had consumed either a high carbohydrate (CHO) or a low CHO diet. Twenty two male professional soccer players formed two teams (A and B), of similar age, body characteristics, and training experience. The two teams played against each other twice with a week interval between. For 3.5 days before the 1 match the players of team A followed a high CHO diet that provided 8 g CHO per Kg body mass (BM) (HC), whereas team B players followed a low CHO diet that provided 3 g CHO / Kg BM (LC) for the same time period. Before the 2 match the dietary treatment was reversed and followed for the same time period. Training during the study was controlled and distances covered were measured using GPS technology. Every player covered a greater total distance in HC compared to the distance covered in LC (HC: 9380 ± 98 m vs. LC: 8077 ± 109 m; p< 0.01). All distances covered from easy jogging (7.15 Km.h) to sprinting (24.15 Km.h) were also higher in HC compared to LC (p< 0.01). When players followed the HC treatment won the match (Team A vs. Team B: 3-1 for the first game and 1-2 for the 2 game). The HC diet probably helped players to cover a greater distance compared to LC. Soccer players should avoid eating a low (3 g CHO / Kg BM) CHO diet 3-4 days before an important soccer match and have a high CHO intake that provides at least 8 g CHO / Kg BM.
Effects of 12 weeks of block periodization on performance and performance indices in well-trained cyclists.
- Scandinavian journal of medicine & science in sports
- Published over 7 years ago
The purpose of this study was to compare the effects of two different methods of organizing endurance training in trained cyclists during a 12-week preparation period. One group of cyclists performed block periodization (BP; n = 8), wherein every fourth week constituted five sessions of high-intensity aerobic training (HIT), followed by 3 weeks of one HIT session. Another group performed a more traditional organization (TRAD; n = 7), with 12 weeks of two weekly HIT sessions. The HIT was interspersed with low-intensity training (LIT) so that similar total volumes of both HIT and LIT were performed in the two groups. BP achieved a larger relative improvement in VO(2max) than TRAD (8.8 ± 5.9% vs 3.7 ± 2.9%, respectively, P < 0.05) and a tendency toward larger increase in power output at 2 mmol/L [la(-) ] (22 ± 14% vs 10 ± 7%, respectively, P = 0.054). Mean effect size (ES) of the relative improvement in VO(2max) , power output at 2 mmol/L [la(-) ], hemoglobin mass, and mean power output during 40-min all-out trial revealed moderate superior effects of BP compared with TRAD training (ES range was 0.62-1.12). The present study suggests that BP of endurance training has superior effects on several endurance and performance indices compared with TRAD.
Although research has explored the association between marital quality and physical health in marriage, existing research fails to consider possible bidirectional associations between changes in individuals' marital quality and self-rated health. To address this gap, this study used latent change models to assess whether adults' marital happiness and problems over a 20-year period predicted subsequent changes in self-rated health, as well as whether self-rated health over the same time period was associated with changes in marital happiness and problems. The sample included 707 continuously married adults who participated in all six waves of the Marital Instability Over the Life Course panel study. Participants averaged 35 years in age at the first wave and were continuously married to the same spouse over the 20-year period. Latent differential models in AMOS 19 showed that unidirectional coupling existed for marital happiness and self-rated health only, such that higher levels of marital happiness predicted subsequent elevations in self-rated health over time. No evidence was found for bidirectional coupling between marital problems and self-rated health. Possible explanations for these patterns of results are discussed, including important directions for future researchers. (PsycINFO Database Record © 2013 APA, all rights reserved).
The academic community is under great pressure to publish. This pressure is compounded by high rejection rates at many journals. A more recent trend is for some journals to send invitations directly to researchers inviting them to submit a manuscript to their journals. Many researchers find these invitations annoying and unsure how best to respond to them. We collected electronic invitations to submit a manuscript to a journal between April 1, 2014, and March 31, 2015. We analyzed their content and cross-tabulated them against journals listed in Beall’s list of potential predatory journals. During this time period, 311 invitations were received for 204 journals, the majority of which were in Beall’s list (n = 244; 79 %). The invitations came throughout the calendar year and some journals sent up to six invitations. The majority of journals claimed to provide peer review (n = 179; 57.6 %) although no mention was made of expedited review process. Similarly, more than half of the journals claimed to be open access (n = 186; 59.8 %). The majority of invitations included an unsubscribe link (n = 187; 60.1 %). About half of the invitations came from biomedical journals (n = 179). We discuss strategies researchers and institutions can consider to reduce the number of invitations received and strategies to handle those invitations that make it to the recipients' inbox, thus helping to maintain the credibility and reputation of researchers and institutions.
Changes or introductions of technology or equipment can affect how a sport is played or influence its performances. This article conducted a systematic review of peer-reviewed literature to identify any case studies of controversial events surrounding the implementation or use of sports technology. 56 articles were identified that highlighted 31 different case studies found over a three decade time period. Thematic analysis revealed six distinctive themes when reviewing the articles. Whilst the sport of golf had the highest number of case studies, it was found that a significant level of attention had been recorded in the cases of Oscar Pistorius use of prosthetic legs in athletics and the use of full length swimsuits in swimming. The trend surrounding the number of articles was shown to be initially intermittent but saw a peak period from 2008 to 2010. However, the frequency of such articles since this peak has been more consistent. It is proposed that long periods of time without intervention or resolution by a governing body often increases the peer-reviewed attention paid to such cases in examples such as those identified in this systematic review.
Abstract Objectives: To examine the clinical outcomes and cost-effectiveness of endourologic procedures performed in the office using standard fluoroscopy and topical anesthesia. Methods: We performed a retrospective review of all patients who underwent primary ureteral stent placement, ureteral stent exchange, or ureteral catheterization with retrograde pyeolography or Bacillus Calmette-Guerin (BCG) instillation under fluoroscopic guidance in the office. For an evaluation of potential time savings, we compared this to a cohort of similar procedures performed in the operating room during the same time period. Results: Procedures were attempted in 65 renal units in 38 patients (13 male, 25 female) with a mean age of 62.2 years (range 29.1-95.4 years). Primary ureteral stent placement was successful in 23/24 (95.8%) renal units. Ureteral stent exchange was successful in 19/22 (86.4%) renal units. Ureteral catheterization with retrograde pyelography or BCG instillation was successful in 19/19 (100%) renal units. The total cost savings for the 38 patients in this study, including excess cost from failure in the office, was approximately $91,496, with an average cost savings of $1,551 per procedure. Office-based procedures were associated with a nearly three-fold reduction in total hospital time as a result of reduced periprocedure waiting times. Conclusions: Ureteral stent placement, ureteral stent exchange, and ureteral catheterization can be performed safely and effectively in the office in both men and women. This avoids general anesthesia and provides significant savings of time and cost for both patients and the health care system.