Reclaiming Lost Territory: The Response of Owyhee Harvester Ants to Forager Intrusions by Neighboring Colonies

Neighboring colonies of the Owyhee harvester ant, Pogonomyrmex salinus, often share nonoverlapping foraging boundaries in the areas between their nests. We found that interactions between neighbors along these foraging boundaries were infrequent but peaceful, and usually resulted in one or both individuals becoming agitated and scurrying away in opposite directions. Interactions between neighbors were necessary to maintain the foraging ranges of their respective colonies. An exclusion experiment showed that when one colony of a pair situated 5-7 m apart was denied access to its foraging range, individuals from the other colony would usually (i.e., in 7 out of 10 cases) enter the unoccupied space within one day. In 6 of 7 of those cases the occupiers set up foraging trails in the newly acquired area in 5 to 39 days (median = 13 days). When foragers from the excluded colony were subsequently allowed access to their original foraging area, theyreclaimed the entire area within 11 days but did not extend their advances beyond the original foraging boundaries. In contrast to the earlier encounters between neighbors, encounters during the reacquisition period were always aggressive, and in 14 of 57 encounters one or both of the combatants was killed. Non-lethal contests were shorter duration than lethal contests (19±2 s versus 422±65 s, respectively). Our results show that competition for foraging space in Owyhee harvester ants is intense despite the seemingly peaceful relationship between neighboring colonies prior to perturbation of their foraging boundaries

Constraining C iii] Emission in a Sample of Five Luminous z = 5.7 Galaxies

Recent observations have suggested that the CIII]$\lambda1907/1909$ emission lines could be alternative diagnostic lines for galaxies in the reionization epoch. We use the F128N narrowband filter on the Hubble Space Telescope's ($\it{HST}$) Wide Field Camera 3 (WFC3) to search for CIII] emission in a sample of five galaxies at z = 5.7 in the Subaru Deep Field and the Subaru/XMM-Newton Deep Field. Using the F128N narrowband imaging, together with the broadband imaging, we do not detect CIII] emission for the five galaxies with $J_{\rm{AB}}$ ranging from 24.10 -- 27.00 in our sample. For the brightest galaxy J132416.13+274411.6 in our sample (z = 5.70, $J_{\rm{AB}} = 24.10$), which has a significantly higher signal to noise, we report a CIII] flux of $3.34\pm1.81 \times 10^{-18}$ $\mathrm{erg\ s^{-1}\ cm^{-2}}$, which places a stringent 3-$\rm\sigma$ upper limit of $5.43\times 10^{-18}$ $\mathrm{erg\ s^{-1}\ cm^{-2}}$on CIII] flux and 6.57 \AA\ on the CIII] equivalent width. Using the stacked image, we put a 3-$\rm\sigma$upper limit on the mean CIII] flux of$\mathrm{2.55\times10^{-18}\ erg\ s^{-1}\ cm^{-2}}$, and a 3-$\rm\sigma$upper limit on the mean CIII] equivalent width of 4.20 {\AA} for this sample of galaxies at z = 5.70. Combined with strong CIII] detection reported among high-z galaxies in the literature, our observations suggest that the equivalent widths of CIII] from galaxies at z$>$ 5.70 exhibit a wide range of distribution. Our strong limits on CIII] emission could be used as a guide for future observations in the reionization epoch

A response to “Likelihood ratio as weight of evidence: a closer look” by Lund and Iyer

Recently, Lund and Iyer (L&I) raised an argument regarding the use of likelihood ratios in court. In our view, their argument is based on a lack of understanding of the paradigm. L&I argue that the decision maker should not accept the expert’s likelihood ratio without further consideration. This is agreed by all parties. In normal practice, there is often considerable and proper exploration in court of the basis for any probabilistic statement. We conclude that L&I argue against a practice that does not exist and which no one advocates. Further we conclude that the most informative summary of evidential weight is the likelihood ratio. We state that this is the summary that should be presented to a court in every scientific assessment of evidential weight with supporting information about how it was constructed and on what it was based

Dopaminergic Haplotype as a Predictor of Spatial Inattention in Children With Attention-Deficit/Hyperactivity Disorder

A distinct pattern of selective attention deficits in attention-deficit/hyperactivity disorder (ADHD) has been difficult to identify. Heterogeneity may reflect differences in underlying genetics.To document an objective deficit of selective attention in a large sample of children with and without ADHD using spatial orienting paradigms. By stratifying samples according to the gene dosage of a risk haplotype of the dopamine transporter gene (DAT1), we could determine whether genetic factors predict spatial inattention in ADHD.A case-control design was used.Children with ADHD were recruited from clinics or support groups in Ireland. Typically developing children were recruited from schools in and around Dublin, Ireland.One hundred fifteen children were recruited (ADHD = 50, control = 65). Groups were matched for age but differed in estimated intelligence.Two versions of a visual spatial orienting task in which attention was directed by valid, neutral, or invalid cues to target locations. Sudden-onset peripheral cues (exogenous) and centrally presented predictive cues (endogenous) were used.To isolate an attention deficit in ADHD, groups were first compared using analysis of variance on the spatial orienting tasks. Multiple regression was used to assess the main effect of DAT1 haplotype status (heterozygous vs homozygous) and the interaction of diagnosis and genotype on those variables that discriminated children with and without ADHD.Children with ADHD displayed deficits in reorienting attention from invalidly cued spatial locations, particularly for targets in the left visual field. DAT1 haplotype status predicted spatial reorienting deficits for left visual field targets (P = .007) but there was also a significant interaction of diagnosis and genotype (P = .02), which revealed the greatest impairment in children with ADHD homozygous for the DAT1 haplotype.Heterogeneity in selective attention in ADHD can be explained by a replicated genetic risk factor for ADHD, the 10/3 DAT1 haplotype

Evaluating implicit feedback models using searcher simulations

In this article we describe an evaluation of relevance feedback (RF) algorithms using searcher simulations. Since these algorithms select additional terms for query modification based on inferences made from searcher interaction, not on relevance information searchers explicitly provide (as in traditional RF), we refer to them as implicit feedback models. We introduce six different models that base their decisions on the interactions of searchers and use different approaches to rank query modification terms. The aim of this article is to determine which of these models should be used to assist searchers in the systems we develop. To evaluate these models we used searcher simulations that afforded us more control over the experimental conditions than experiments with human subjects and allowed complex interaction to be modeled without the need for costly human experimentation. The simulation-based evaluation methodology measures how well the models learn the distribution of terms across relevant documents (i.e., learn what information is relevant) and how well they improve search effectiveness (i.e., create effective search queries). Our findings show that an implicit feedback model based on Jeffrey's rule of conditioning outperformed other models under investigation

Incident venous thromboembolic events in the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER)

<p>Background: Venous thromboembolic events (VTE), including deep venous thrombosis and pulmonary embolism, are common in older age. It has been suggested that statins might reduce the risk of VTE however positive results from studies of middle aged subjects may not be generalisable to elderly people. We aimed to determine the effect of pravastatin on incident VTE in older people; we also studied the impact of clinical and plasma risk variables.</p> <p>Methods: This study was an analysis of incident VTE using data from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER), a randomized, double-blind, placebo-controlled trial of pravastatin in men and women aged 70-82. Mean follow-up was 3.2 years. Risk for VTE was examined in non-warfarin treated pravastatin (n = 2834) and placebo (n = 2865) patients using a Cox's proportional hazard model, and the impact of other risk factors assessed in a multivariate forward stepwise regression analysis. Baseline clinical characteristics, blood biochemistry and hematology variables, plasma levels of lipids and lipoproteins, and plasma markers of inflammation and adiposity were compared. Plasma markers of thrombosis and hemostasis were assessed in a nested case (n = 48) control (n = 93) study where the cohort was those participants, not on warfarin, for whom data were available.</p> <p>Results: There were 28 definite cases (1.0%) of incident VTE in the pravastatin group recipients and 20 cases (0.70%) in placebo recipients. Pravastatin did not reduce VTE in PROSPER compared to placebo [unadjusted hazard ratio (95% confidence interval) 1.42 (0.80, 2.52) p = 0.23]. Higher body mass index (BMI) [1.09 (1.02, 1.15) p = 0.0075], country [Scotland vs Netherlands 4.26 (1.00, 18.21) p = 0.050 and Ireland vs Netherlands 6.16 (1.46, 26.00) p = 0.013], lower systolic blood pressure [1.35 (1.03, 1.75) p = 0.027] and lower baseline Mini Mental State Examination (MMSE) score [1.19 (1.01, 1.41) p = 0.034] were associated with an increased risk of VTE, however only BMI, country and systolic blood pressure remained significant on multivariate analysis. In a nested case control study of definite VTE, plasma Factor VIII levels were associated with VTE [1.52 (1.01, 2.28), p = 0.044]. However no other measure of thrombosis and haemostasis was associated with increased risk of VTE.</p> <p>Conclusions: Pravastatin does not prevent VTE in elderly people at risk of vascular disease. Blood markers of haemostasis and inflammation are not strongly predictive of VTE in older age however BMI, country and lower systolic blood pressure are independently associated with VTE risk.</p&gt

CAD techniques for microwave circuits

In little more than 10 years computer-aided design (CAD) of microwave circuits has moved from dumb terminals on mainframe computers to PCs, and now to powerful RISC workstations. Commercial CAD software now integrates the various stages of microwave circuit design: schematic capture, simulation and layout. This paper reviews the different CAD packages that are available for microwave circuit design. The basic principles employed in the modelling of microstrip circuits are introduced and the reasons for the extensive use of frequency-domain simulations are explored. The developments in nonlinear, electromagnetic and system-level simulation methods are described.The authors would like to acknowledge the financial support of the Engineering and Physical Sciences Research Council, and the Comisidn Interministerial de Ciencia y Technologia (CICr?‘), Spain, under the project TIC95-0983-C03-02. We would like to thank Hewlett Packard, Barnard Microsystems, Sonnet Software, Optimization Systems Associates, Kimberley Communications Consultants and Ansoft Corporation for their generous educational discounting. The assistance of Dr. D. M. Brookbanks at GEC-Marconi Materials Technology Ltd. (Caswell) is gratefully acknowledged

CAD techniques for microwave circuits

In little more than 10 years computer-aided design (CAD) of microwave circuits has moved from dumb terminals on mainframe computers to PCs, and now to powerful RISC workstations. Commercial CAD software now integrates the various stages of microwave circuit design: schematic capture, simulation and layout. This paper reviews the different CAD packages that are available for microwave circuit design. The basic principles employed in the modelling of microstrip circuits are introduced and the reasons for the extensive use of frequency-domain simulations are explored. The developments in nonlinear, electromagnetic and system-level simulation methods are described.The authors would like to acknowledge the financial support of the Engineering and Physical Sciences Research Council, and the Comisidn Interministerial de Ciencia y Technologia (CICr?‘), Spain, under the project TIC95-0983-C03-02. We would like to thank Hewlett Packard, Barnard Microsystems, Sonnet Software, Optimization Systems Associates, Kimberley Communications Consultants and Ansoft Corporation for their generous educational discounting. The assistance of Dr. D. M. Brookbanks at GEC-Marconi Materials Technology Ltd. (Caswell) is gratefully acknowledged

Searching for a Stochastic Background of Gravitational Waves with LIGO

The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed the fourth science run, S4, with significantly improved interferometer sensitivities with respect to previous runs. Using data acquired during this science run, we place a limit on the amplitude of a stochastic background of gravitational waves. For a frequency independent spectrum, the new limit is $\Omega_{\rm GW} < 6.5 \times 10^{-5}$. This is currently the most sensitive result in the frequency range 51-150 Hz, with a factor of 13 improvement over the previous LIGO result. We discuss complementarity of the new result with other constraints on a stochastic background of gravitational waves, and we investigate implications of the new result for different models of this background.Comment: 37 pages, 16 figure

Search for gravitational wave bursts in LIGO's third science run

We report on a search for gravitational wave bursts in data from the three LIGO interferometric detectors during their third science run. The search targets subsecond bursts in the frequency range 100-1100 Hz for which no waveform model is assumed, and has a sensitivity in terms of the root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published in Classical and Quantum Gravit