Observations on the Overwintering Potential of the Striped Cucumber Beetle (Coleoptera: Chrysomelidae) in Southern Minnesota

The striped cucumber beetle, Acalymma vittatum (Fabricius) (Coleoptera: Chrysomelidae), is an important pest of cucurbit crops. However, the overwinter- ing capacity of this pest in temperate regions is poorly understood. In this study, the in-field survival of A. vittatum was examined during three consecutive winters. In addition, the supercooling points of A. vittatum were determined as an index of cold hardiness for adults. During each winter, the survival of adults decreased significantly through time, with no individuals surviving until spring. By comparing the supercooling points and in-field survival of adults to soil temperatures, it appears that winter temperatures in Minnesota are cold enough to induce freezing of the beetles. Moreover, a considerable amount of mortality occurred before minimum monthly soil temperatures dropped below the supercooling point of overwintering individuals, suggesting the occurrence of prefreeze mortality. An improved understanding of the response of A. vittatum to winter temperatures in temperate regions may aid in early season management of this pest

Genetic Map of Bacteriophage [var phi]X174

Bacteriophage [var phi]X174 temperature-sensitive and nonsense mutations in eight cistrons were mapped by using two-, three-, and four-factor genetic crosses. The genetic map is circular with a total length of 24 × 10−4wt recombinants per progeny phage. The cistron order is D-E-F-G-H-A-B-C. High negative interference is seen, consistent with a small closed circular deoxyribonucleic acid molecule as a genome

Attack analysis of cryptographic protocols using strand spaces

Security protocols make use of cryptographic techniques to achieve goals such as confidentiality, authentication and integrity. However, the fact that strong cryptographic algorithms exist does not guarantee the security of a communications system. In fact, it is recognised that the engineering of security protocols is a challenging task, since protocols that appear secure can contain subtle flaws that attackers can exploit. A number of techniques exist for the analysis of security protocol specifications. Individually they are not capable of detecting every possible flaw or attack against a protocol. However, when combined, these techniques all complement each other, allowing a protocol engineer to obtain a more accurate overview of the security of a protocol that is being designed. This is the rationale for multi-dimensional security protocol engineering, a concept introduced by previous projects of ours over several years. We propose an attack construction approach to security protocol analysis within a multi-dimensional context. This analysis method complements the existing inference construction analysis tools developed earlier in the group. We give a brief overview of the concepts associated with the project, including a summary of existing security protocol analysis techniques, and a description of the strand space model, which is the intended formalism for the analysis

Similarity-based gene detection: using COGs to find evolutionarily-conserved ORFs

BACKGROUND: Experimental verification of gene products has not kept pace with the rapid growth of microbial sequence information. However, existing annotations of gene locations contain sufficient information to screen for probable errors. Furthermore, comparisons among genomes become more informative as more genomes are examined. We studied all open reading frames (ORFs) of at least 30 codons from the genomes of 27 sequenced bacterial strains. We grouped the potential peptide sequences encoded from the ORFs by forming Clusters of Orthologous Groups (COGs). We used this grouping in order to find homologous relationships that would not be distinguishable from noise when using simple BLAST searches. Although COG analysis was initially developed to group annotated genes, we applied it to the task of grouping anonymous DNA sequences that may encode proteins. RESULTS: "Mixed COGs" of ORFs (clusters in which some sequences correspond to annotated genes and some do not) are attractive targets when seeking errors of gene predicion. Examination of mixed COGs reveals some situations in which genes appear to have been missed in current annotations and a smaller number of regions that appear to have been annotated as gene loci erroneously. This technique can also be used to detect potential pseudogenes or sequencing errors. Our method uses an adjustable parameter for degree of conservation among the studied genomes (stringency). We detail results for one level of stringency at which we found 83 potential genes which had not previously been identified, 60 potential pseudogenes, and 7 sequences with existing gene annotations that are probably incorrect. CONCLUSION: Systematic study of sequence conservation offers a way to improve existing annotations by identifying potentially homologous regions where the annotation of the presence or absence of a gene is inconsistent among genomes

Mapping phosphoproteins in Mycoplasma genitalium and Mycoplasma pneumoniae

<p>Abstract</p> <p>Background</p> <p>Little is known regarding the extent or targets of phosphorylation in mycoplasmas, yet in many other bacterial species phosphorylation is known to play an important role in signaling and regulation of cellular processes. To determine the prevalence of phosphorylation in mycoplasmas, we examined the CHAPS-soluble protein fractions of <it>Mycoplasma genitalium </it>and <it>Mycoplasma pneumoniae </it>by two-dimensional gel electrophoresis (2-DE), using a combination of Pro-Q Diamond phosphoprotein stain and ³³P labeling. Protein spots that were positive for phosphorylation were identified by peptide mass fingerprinting using MALDI-TOF-TOF mass spectrometry.</p> <p>Results</p> <p>We identified a total of 24 distinct phosphoproteins, about 3% and 5% of the total protein complement in <it>M. pneumoniae </it>and <it>M. genitalium</it>, respectively, indicating that phosphorylation occurs with prevalence similar to many other bacterial species. Identified phosphoproteins include pyruvate dehydrogenase E1 alpha and beta subunits, enolase, heat shock proteins DnaK and GroEL, elongation factor Tu, cytadherence accessory protein HMW3, P65, and several hypothetical proteins. These proteins are involved in energy metabolism, carbohydrate metabolism, translation/transcription and cytadherence. Interestingly, fourteen of the 24 phosphoproteins we identified (58%) were previously reported as putatively associated with a cytoskeleton-like structure that is present in the mycoplasmas, indicating a potential regulatory role for phosphorylation in this structure.</p> <p>Conclusion</p> <p>This study has shown that phosphorylation in mycoplasmas is comparable to that of other bacterial species. Our evidence supports a link between phosphorylation and cytadherence and/or a cytoskeleton-like structure, since over half of the proteins identified as phosphorylated have been previously associated with these functions. This opens the door to further research into the purposes and mechanisms of phosphorylation for mycoplasmas.</p

Lamins in disease : why do ubiquitously expressed nuclear envelope proteins give rise to tissue-specific disease phenotypes?

The nuclear lamina is a filamentous structure composed of lamins that supports the inner nuclear membrane. Several integral membrane proteins including emerin, LBR, LAP1 and LAP2 bind to nuclear lamins in vitro and can influence lamin function and dynamics in vivo. Results from various studies suggest that lamins function in DNA replication and nuclear envelope assembly and determine the size and shape of the nuclear envelope. In addition, lamins also bind chromatin and certain DNA sequences, and might influence chromosome position. Recent evidence has revealed that mutations in A-type lamins give rise to a range of rare, but dominant, genetic disorders, including Emery-Dreifuss muscular dystrophy, dilated cardiomyopathy with conduction-system disease and Dunnigan-type familial partial lipodystrophy. An examination of how lamins A/C, emerin and other integral membrane proteins interact at the INM provides the basis for a novel model for how mutations that promote disease phenotypes are likely to influence these interactions and therefore cause cellular pathology through a combination of weakness of the lamina or altered gene expression

Tuning the Kondo effect with a mechanically controllable break junction

We study electron transport through C60 molecules in the Kondo regime using a mechanically controllable break junction. By varying the electrode spacing, we are able to change both the width and height of the Kondo resonance, indicating modification of the Kondo temperature and the relative strength of coupling to the two electrodes. The linear conductance as a function of T/T_K agrees with the scaling function expected for the spin-1/2 Kondo problem. We are also able to tune finite-bias Kondo features which appear at the energy of the first C60 intracage vibrational mode.Comment: 4 pages with 4 figure

Electrically-detected magnetic resonance in ion-implanted Si:P nanostructures

We present the results of electrically-detected magnetic resonance (EDMR) experiments on silicon with ion-implanted phosphorus nanostructures, performed at 5 K. The devices consist of high-dose implanted metallic leads with a square gap, into which Phosphorus is implanted at a non-metallic dose corresponding to 10^17 cm^-3. By restricting this secondary implant to a 100 nm x 100 nm region, the EDMR signal from less than 100 donors is detected. This technique provides a pathway to the study of single donor spins in semiconductors, which is relevant to a number of proposals for quantum information processing.Comment: 9 pages, 3 figure