No enhanced recognition memory,but better source memory for faces of cheaters

Previous studies sought to test for the existence of a “cheater-detection module” by testing for enhanced memory for the faces of cheaters, but past results have been inconclusive. Here, we present four experiments showing that old–new discrimination was not affected by whether a face was associated with a history of cheating, trustworthy or irrelevant behavior. In contrast, source memory for faces associated with a history of cheating (i.e., memory for the cheating context in which the face was encountered) was consistently better than source memory for other types of faces. This pattern held under a variety of conditions, including different types of judgments participants made about the stimulus persons (attractiveness in Experiment 1; likeability in Experiments 2–4), different retention intervals (a few minutes in Experiments 1, 2 and 4; 1 week in Experiment 3), whether the behaviors were exceptional or ordinary (Experiments 1–3) and whether the social status of the characters was low or high (Experiment 4). Given no differences in old–new discrimination, enhanced source memory for faces of cheaters may be useful for avoiding cheaters in future interactions.     

Evaluation of neem seed powder for Fusarium wilt and Meloidogyne control on tomato

Fusarium wilt and root-knot are important diseases of tomato. The use of chemical is becoming less appealing because of the health implications. Also, the chemicals required are often not within the reach of farmers in most of the developing part of the world. This research is aimed at finding an alternative mode of control. Tomato variety Roma VF inoculated with Meloidogyne and Fusarium were treated with 2 g/kg soil neem seed powder in the screenhouse and 2 Mg ha ^{? 1} in the field. An untreated and Furadan treated plot in the field served as control. Neem seed powder significantly reduced the disease severity of Fusarium and root-knot in both screenhouse and field. Results suggest the possible use of neem seed powder for control of the root-knot nematodes - Fusarium wilt disease complex.     

Testing statistical significance scores of sequence comparison methods with structure similarity

Background  

In the past years the Smith-Waterman sequence comparison algorithm has gained popularity due to improved implementations and rapidly increasing computing power. However, the quality and sensitivity of a database search is not only determined by the algorithm but also by the statistical significance testing for an alignment. The e-value is the most commonly used statistical validation method for sequence database searching. The CluSTr database and the Protein World database have been created using an alternative statistical significance test: a Z-score based on Monte-Carlo statistics. Several papers have described the superiority of the Z-score as compared to the e-value, using simulated data. We were interested if this could be validated when applied to existing, evolutionary related protein sequences.     

Picoplankton culture assessment using single strand conformation polymorphism and partial 18S sequencing

Environmental water samples were taken throughout 2001 fromfractioned water samples at the Helgoland time series site.The less than 3-µm fraction was inoculated into variousmedia. Serial dilutions from these inoculations produced a largenumber of rough cultures from which several hundred well-growingpicoplankton cultures were started. We established a combinationof crude DNA extraction, single strand conformation polymorphism(SSCP) fingerprinting and subsequent sequence analysis to screenthese large numbers of cultures, assess their purity/clonalityand determine their identity. Picoplankton species (i.e., cellssmaller than 3 µm) are difficult to distinguish becauseof their small size and the lack of morphological characters.Therefore, molecular techniques provide the most reliable methodto achieve their identification. Cultures were enriched forphotoautotroph cells, i.e., no carbon source was added, andcultures were grown in the light. From these cultures, crudeDNA was extracted, which was used for partial 18S polymerasechain reaction (PCR). On average, 50% of the cultures produceda PCR product. SSCP analysis of PCR products revealed the clonalityof a given culture. If clonal, then there was only a singleSSCP band; if not clonal, then there were multiple SSCP bands.Single SSCP bands were subsequently sequenced, and sequenceswere used to identify the culture. For this study, 300 cultureswere screened resulting in the identification of 63 potentiallyclonal cultures. These methods proved to be relatively easyto apply to assess the clonality and purity of the cultures.     

Identifying dynamical modules from genetic regulatory systems: applications to the segment polarity network

Background  

It is widely accepted that genetic regulatory systems are 'modular', in that the whole system is made up of smaller 'subsystems' corresponding to specific biological functions. Most attempts to identify modules in genetic regulatory systems have relied on the topology of the underlying network. However, it is the temporal activity (dynamics) of genes and proteins that corresponds to biological functions, and hence it is dynamics that we focus on here for identifying subsystems.     

Key transitions in morphological development improve age estimates in white sturgeon Acipenser transmontanus

We reared white sturgeon Acipenser transmontanus under laboratory conditions and found that a random-forest model containing scute counts and total length predicted age significantly better than total length alone. Scute counts are rapid, inexpensive and non-lethal meristics to gather in the field. This technique could improve age estimates of imperilled sturgeon populations.