Rate Of Change In Number Research Articles

Pan-tumor circulating tumor DNA testing in the community oncology setting.

e14556 Background: Circulating tumor DNA (ctDNA) technology allows for monitoring the genomic profile of cancer over time non-invasively, and in a way that is more representative of existing tumor clones than tissue sampling. The clinical and research applications of this new technology are numerous, and they are potentiated through serial ctDNA testing of individual patients. It is important to identify and characterize real-world data sets that will permit the development of both ctDNA’s clinical and research applications. Methods: This is an observational study of breast, non-small cell lung cancer (NSCLC), colorectal and prostate cancer patients who had ctDNA testing in The US Oncology Network from August 2014 to August 2023. All unique ctDNA reports per patient were collected, along with the report dates and patient characteristics. Rate of change in number of unique reports per month through time was evaluated as well as frequencies of serial testing and median time lapse between diagnosis and date of first ctDNA test by cancer type. Results: Number of new unique ctDNA testing reports per month increased for The US Oncology Network from 2014 through 2018 at a rate of 0.86 (95% CI [0.70, 1.02]). From 2018 to 2023 this rate increased to 5.87 (95% CI [5.16, 6.59]) new reports per month. The total number of unique patients with one of the 4 cancer indications and at least one ctDNA test during the study time period was 10,852. The cancer indication with greatest number of patients with ctDNA testing is NSCLC with 5,503 patients, followed by breast with 2,408, and colorectal and prostate with 1,544 and 1,397 respectively. Black patients were equally represented across all 4 cancers at rates of 13.6% for colorectal, 12.7% for breast, and 12% for NSCLC and prostate. Patients over 65 made up 66% for prostate and NSCLC but only 38% and 32% for colorectal and breast respectively. Most patients presented with a single ctDNA test (n = 9482), but an important proportion presented with 2 serial ctDNA tests or more (n = 1370, 12.6%).The median time between either cancer diagnosis date or date of first visit in The Network and the date of the first ctDNA test report was 39 days for NSCLC, 1,690 days for breast, 377 days for colorectal and 772 days for prostate, and presented with a skewed, long right tailed distribution. Median times were similar for Black and White patients across all cancers. Conclusions: The number of patients with ctDNA testing data available is increasing through time without evidence of plateauing. Although the total number of patients represented is still a very small fraction of the total patient population, the rate of increase in number of new reports through time is equivalent to an exponential increase in the total number of reports. 12.6% of patients presented with two tests or more, potentially allowing for pre and post treatment assessments. There’s an opportunity to better align cancer research and cancer treatment paradigms with this new technology.

The enduring gap in educational attainment in schizophrenia according to the past 50 years of published research: a systematic review and meta-analysis

Educational attainment is associated with wellbeing and health, but patients with schizophrenia achieve lower levels of education than people without. Several effective interventions can ameliorate this situation. However, the magnitude of the education gap in schizophrenia and its change over time are unclear. We aimed to reconstruct the trajectories of educational attainment in patients with schizophrenia and, if reported, their healthy comparator controls. We did a systematic review and meta-analysis including all studies reporting on patients with schizophrenia (of mean age ≥18 years) and describing the number of years of education of the participants, with or without healthy controls. There were no other design constraints on studies. We excluded studies that included only patients with other schizophrenia spectrum disorders and studies that did not specify the number of years of education of the participants. 22 reviewers participated in retrieving data from a search in PubMed and PsycINFO (Jan 1, 1970, to Nov 24, 2020). We estimated the birth date of participants from their mean age and publication date, and meta-analysed these data using random-effects models, focusing on educational attainment, the education gap, and changes over time. The primary outcome was years of education. The protocol was registered on PROSPERO (CRD42020220546). From 32 593 initial references, we included 3321 studies reporting on 318 632 patients alongside 138 675 healthy controls (170 941 women and 275 821 men from studies describing sex or gender; data on ethnicity were not collected). Patients' educational attainment increased over time, mirroring that of controls. However, patients with schizophrenia in high-income countries had 19 months less education than controls (-1·59 years, 95% CI -1·66 to -1·53; p<0·0001), which is equivalent to a Cohen's d of -0·56 (95% CI -0·58 to -0·54) and implies an odds ratio of 2·58 for not completing 12 years of education (ie, not completing secondary education) for patients compared with controls. This gap remained stable throughout the decades; the rate of change in number of total years of education in time was not significant (annual change: 0·0047 years, 95% CI -0·0005 to 0·0099; p=0·078). For patients in low-income and middle-income countries, the education gap was significantly smaller than in high-income countries (smaller by 0·72 years, 0·85 to 0·59; p<0·0001), yet there was evidence that this gap was widening over the years, approaching that of high-income countries (annual change: -0·024 years, -0·037 to -0·011; p=0·0002). Patients with schizophrenia have faced persistent inequality in educational attainment in the last century, despite advances in psychosocial and pharmacological treatment. Reducing this gap should become a priority to improve their functional outcomes. Ciencia y Tecnología para el Desarrollo (CYTED) to the Latin American Network for the Study of Early Psychosis (ANDES).

Trends in Radiation Oncology Treatment Fractionation at a Single Academic Center, 2014-2020

Recent landmark studies in radiation oncology suggest hypofractionation is appropriate for treatment of many cancers. The COVID-19 pandemic may have increased pressure to adopt hypofractionation because of concerns about disease spread at treatment centers. We know of no recent U.S. study of trends in radiation fractionation that includes comparisons of multiple disease sites and data post-COVID. Therefore, we sought to describe trends in treatment fractionation at a single academic center from 2014-2020.From our institutional database, for the years 2014-2020, we extracted the total number of patients treated, total number of fractions delivered, and mean number of fractions per treatment course for all cancers and specifically for treatment of breast cancer, prostate cancer, and bone metastases. For breast and prostate, we included only radiation courses delivered to the primary site.The dataset included 16,224 courses of radiation treatment and 257,352 treatment fractions. The mean number of fractions per treatment course overall declined steadily throughout the study period, from 18.3 in 2014 to 14.9 in 2020. For breast cancer, the mean number of fractions per treatment course was steady from 2014-2016 but began to decline more rapidly from 2017-2020. Fractionation for prostate cancer followed a similar time trend, but there was a more substantial decline from 2014 (mean 36.6 fractions per treatment course) to 2020 (mean 16.7 fractions per treatment course). For bone metastases, fractionation was relatively consistent throughout the study period. For breast patients, during the onset of COVID-19 in 2020, the monthly rate of decrease in number of fractions increased to 0.19 from a historical mean of 0.05, as the mean number of sessions dropped from 22 to 19. For bone metastases, in 2020, the mean number of sessions dropped from 6.3 to 5.3, with a monthly rate of decrease of 0.13 compared to historical mean of 0.03. COVID-19 did not spike the monthly rate of change in number of fractions for prostate which began a steady decline in 2017 with increased use of SBRT.We observed increased adoption of hypofractionation at our institution during the study period for both breast and prostate cancer. For bone metastases, hypofractionation had largely been adopted before the study period. There was evidence of an accelerated trend toward hypofractionation for some cancers during the COVID-19 pandemic.

Using national register data to estimate the heritability of periodontitis.

To identify whether periodontal traits derived from electronic dental records are biologically informative and heritable. The study included 11,974 adult twins (aged 30-92years) in the Swedish Twin Registry. Periodontal records from dental examinations were retrieved from a national register and used to derive continuous measures of periodontal health. A latent class approach was used to derive categorial measures of periodontal status. The correlation patterns in these traits were contrasted in monozygotic and dizygotic twin pairs using quantitative genetic models to estimate the heritability of the traits. For continuous traits, heritability estimates ranged between 41.5% and 48.3% with the highest estimates for number of missing tooth surfaces and rate of change in number of deep periodontal pockets (≥6mm). For categorial traits, the latent class approach identified three classes (good periodontal health, mild periodontitis signs and severe signs of periodontitis) and there was a clear difference in the hazard for subsequent tooth loss between these three classes. Despite this, the class allocations were only slightly more heritable than a conventional dichotomous disease definition (45.2% vs. 42.6%). Periodontitis is a moderately heritable disease. Quantitative periodontal traits derived from electronic records are an attractive target for future genetic association studies.

India's performance in controlling Visceral Leishmaniasis as compared to Brazil over past three decades: findings from global burden of disease study.

Visceral leishmaniasis (VL) is a neglected tropical disease which contributes to the mortality and morbidity significantly in India and Brazil. This study was planned to compare the trends of incidence, prevalence, death and disability-adjusted life years (DALY) of VL burden in India and Brazil from 1990 to 2019 using Global burden of disease study (GBD) data. The metrics are presented as age-standardized rates per 100,000 inhabitants with their respective uncertainty intervals (95% UI) and relative percentages of change. The decline in the Incidence rate is more in case of India (16.82 cases per 100,000 in 1990 to 0.60 cases in 2019) as compared to Brazil (3.12 cases per 100,000 in 1990 to 2.65 cases in 2019). The annualized rate of change in number of prevalent cases for India is - 0.95 (95% UI - 0.98 to - 0.91) whereas for Brazil it is - 0.06 (95% UI - 0.41 to 0.52). The annualized rate of change in number of DALY for India is - 0.94 (95% UI - 0.96 to - 0.92) whereas for Brazil it is - 0.09 (95% UI - 0.25 to 0.28). The annualized rate of change in number of deaths for India is - 0.93 (95% UI - 0.95 to - 0.92) whereas for Brazil it is increasing i.e. 0.04 (95% UI - 0.12 to 0.51). India achieves significant reduction in the age standardized incidence, prevalence, mortality and DALY of VL as compared to Brazil during the period of 1990 to 2019. A multi-centric study is required to assess bottleneck in the existing strategies of VLSCP in Brazil.

Vision Impairment and Participation in Cognitively Stimulating Activities: The Health ABC Study.

Engagement in cognitively stimulating activities is associated with decreased rates of cognitive decline in older adults. However, most cognitively stimulating tasks require good vision, potentially affecting the ability of visually impaired adults to engage in these activities. We examined the relationship between vision and participation in cognitively stimulating activities. Data from the Health, Aging, and Body Composition study (1999-2005) were analyzed. Associations between visual function (visual acuity [VA], contrast sensitivity [CS], and stereo acuity [SA] impairments) and annual rates of change in number of cognitively stimulating activities (by self-report) performed at least once a month were examined. Analyses included 924 participants aged 75.2 ± 2.8 years. At baseline, impaired CS (27%) and SA (29%) were associated with participation in fewer cognitive activities (β = -0.33, 95% CI = -0.63, -0.03 and β = -0.32, 95% CI = -0.61, -0.03, respectively), while VA (8%) was not (β = -0.34, 95% CI = -0.81, 0.13). In longitudinal models, groups with and without VA, CS, and SA impairments exhibited declines in monthly cognitive activities over time. Annual rates of decline were relatively higher in the VA (β = -0.16, 95% CI = -0.26, -0.05) and CS (β = -0.14, 95% CI = -0.19, -0.09) impaired groups than observed in the respective unimpaired groups (no VA: β = -0.12, 95% CI = -0.15, -0.10; no CS: β = -0.12, 95% CI = -0.15, -0.09), but did not achieve statistical significance. Stereo acuity (β = -0.13, 95% CI = -0.17, -0.09) and no SA (β = -0.13, 95% CI = -0.16, -0.10) groups had similar rates of decline. Visually impaired older adults participate in fewer cognitive activities and although participation decline is similar to the non-impaired, lower overall participation indicates a need to identify cognitively stimulating activities accessible to visually impaired older adults.

Where medical education meets artificial intelligence: ‘Does technology care?’

'COLD' TECHNOLOGIES AND 'WARM' HANDS-ON MEDICINE NEED TO WALK HAND-IN-HAND: Technologies, such as deep learning artificial intelligence (AI), promise benign solutions to thorny, complex problems; but this view is misguided. Though AI has revolutionised aspects of technical medicine, it has brought in its wake practical, conceptual, pedagogical and ethical conundrums. For example, widespread adoption of technologies threatens to shift emphasis from 'hands-on' embodied clinical work to disembodied 'technology enhanced' fuzzy scenarios muddying ethical responsibilities. Where AI can offer a powerful sharpening of diagnostic accuracy and treatment options, 'cold' technologies and 'warm' hands-on medicine need to walk hand-in-hand. This presents a pedagogical challenge grounded in historical precedent: in the wake of Vesalian anatomy introducing the dominant metaphor of 'body as machine,' a medicine of qualities was devalued through the rise of instrumental scientific medicine. The AI age in medicine promises to redouble the machine metaphor, reducing complex patient experiences to linear problem-solving interventions promising 'solutionism.' As an instrumental intervention, AI can objectify patients, frustrating the benefits of dialogue, as patients' complex and often unpredictable fleshly experiences of illness are recalculated in solution-focused computational terms. SUSPICIONS ABOUT SOLUTIONS: The rate of change in numbers and sophistication of new technologies is daunting; they include surgical robotics, implants, computer programming and genetic interventions such as clustered regularly interspaced short palindromic repeats (CRISPR). Contributing to the focus of this issue on 'solutionism,' we explore how AI is often promoted as an all-encompassing answer to complex problems, including the pedagogical, where learning 'hands-on' bedside medicine has proven benefits beyond the technical. Where AI and embodied medicine have differing epistemological, ontological and axiological roots, we must not imagine that they will readily walk hand-in-hand down the aisle towards a happy marriage. Their union will be fractious, requiring lifelong guidance provided by a perceptive medical education suspicious of 'smart' solutions to complex problems.

Assessing factors associated with changes in the numbers of birds visiting gardens in winter: Are predators partly to blame?

The factors governing the recent declines observed in many songbirds have received much research interest, in particular whether increases of avian predators have had a negative effect on any of their prey species. In addition, further discussion has centered on whether or not the choice of model formulation has an effect on model inference. The study goal was to evaluate changes in the number of 10 songbird species in relation to a suite of environmental covariates, testing for any evidence in support of a predator effect using multiple model formulations to check for consistency in the results. We compare two different approaches to the analysis of long‐term garden bird monitoring data. The first approach models change in the prey species between 1970 and 2005 as a function of environmental covariates, including the abundance of an avian predator, while the second uses a change–change approach. Significant negative relationships were found between Eurasian Sparrowhawk Accipiter nisus and three of the 10 species analyzed, namely house Sparrow Passer domesticus, starling Sturnus vulgaris, and blue tit Cyanistes caeruleus. The results were consistent under both modeling approaches. It is not clear if this is a direct negative impact on the overall populations of these species or a behavioral response of the prey species to avoid feeding stations frequented by Sparrowhawks (which may in turn have population consequences, by reducing available resources). The species showing evidence of negative effects of Sparrowhawks were three of the four species most at risk to Sparrowhawk predation according to their prevalence in the predator's diet. The associations could be causal in nature, although in practical terms the reduction in the rate of change in numbers visiting gardens accredited to Sparrowhawks is relatively small, and so unlikely to be the main driver of observed population declines.

Association Between Accelerated Multimorbidity and Age-Related Cognitive Decline in Older Baltimore Longitudinal Study of Aging Participants without Dementia.

To explore the association between rate of physical health deterioration, operationalized as rising multimorbidity overtime, and longitudinal decline in cognitive function in older adults without dementia. Longitudinal (Baltimore Longitudinal Study of Aging (BLSA)). Community. BLSA participants aged 65 and older followed for an average of 3 years and free of dementia or mild cognitive impairment (MCI) at baseline and follow-up (N = 756). Standardized neurocognitive tests evaluating mental status, memory, executive function, processing speed, and verbal fluency were administered. Multimorbidity was assessed at each visit as number of diagnosed chronic diseases from a predefined list. Faster accumulation of chronic diseases was defined as upper quartile of rate of change in number of diseases over time (≥0.25 diseases/year). Faster accumulation of chronic diseases was significantly associated with greater rate of decline on the Category (P = .01) and Letter (P = .01) Fluency Tests. Similar trends were also found for the Trail-Making Test Parts A (P = .08) and B (P = .07); no association was found with rate of change in visual and verbal memory. Although further investigations are required to validate the results and fully understand the underlying mechanisms, these findings suggest that accelerated deterioration of physical health is associated with accelerated decline with aging in specific cognitive domains in older adults without dementia.

The effect of entrepreneurial orientation on SMEs growth and export in Israeli peripheral regions

This research explores the influence of entrepreneurial orientation (EO) on SMEs located at core and peripheral regions, by focusing on a single dimension of EO: proactiveness. We conducted a quantitative study of 626 Israeli SMEs. Business growth, as measured by the rate of change in number of employees, was found to be significantly higher in the core region. As expected, proactiveness was found to strongly affect SME growth as well as firm expansion to international markets. Our analysis shows that the difference in business growth between regions can be attributed also to a lower level of ownersʼ proactiveness in peripheral regions since it was found to mediate the effect of peripheral location on firm growth. Differences in proactiveness levels may be explained by the historical development of peripheral regions. Our results have useful implications for policies that aim to promote growth and development in peripheral regions.

A pilot RCT of an intervention to reduce HIV sexual risk and increase self-acceptance among MSM in Chennai, India.

This is a 2-arm pilot randomized controlled trial (N = 96) of a behavioral intervention (4 group and 4 individual sessions) integrating risk reduction counseling with counseling to foster self-acceptance in MSM in India compared to enhanced standard of care (ESOC). Both conditions involved HIV and STI testing and counseling at baseline and 6-months, and assessments of condomless sex at baseline, 3-, and 6-months. A significant condition by time interaction suggested a difference in the rate of change in number of anal sex acts without condoms in the intervention versus ESOC (p < 0.0001). Post hoc contrasts suggested that the overall difference was due to intervention-response at 3-months. The incidence of bacterial STIs was 17.5 % in the intervention condition and a 28.6 % in ESOC. Addressing self-acceptance and related psychosocial concerns in the context sexual risk reduction counseling for MSM in India was feasible and acceptable. Testing the intervention for efficacy is justified.

Memory Politics and International Relations in East Asia

In the globalizing society, it is inevitable to have good relations with neighboring countries. After WW II, global areas have been formed differently by America. In other words, America had set multilateralism system in Europe, in contrast to bilateralism system in East Asia. So, East Asian countries couldn't communicate and exchange without America for a long time. However, in the Post-Cold War, though this mood was dissolved, it is still difficult to say East Asian countries have good relationship one another. In this paper, I argue that the reason is unsolved problems, the emotional matters among the nations. Unlike Europe, it occurred past problems in East Asia repeatedly and continuously. Then, it makes hard to cooperate the nations. On the basis of Constructivism perspective, this paper takes an example, Korea-Japan relations, which has some unsolved past problems. In Korea-Japan relations, there are many tries and efforts to have a good relation politically and socially. Yet, it comes to nothing whenever past problems happened between two nations. In the political part, we can find it by examining the change of policies toward the nation before and after occurring past problems. Likewise, in the social part, as one of evidences, the change rate of number of tourists coming and going to the countries proves it. Irrational factors can affect relations between nations.

Trends in dermatologic surgery research over the past decade

We aimed to study the rate of change in number and categories of publications in dermatologic surgery in dermatology versus non-dermatology journals. PubMed was searched for articles on dermatologic surgery from January 1, 1998 to December 31, 2007, using the search word "dermatology" AND "surgery". Articles were characterized by publication and journal type per year. Regression analysis was used to determine the effect of year of publication on number of publications of each type. The search yielded 7570 publications on dermatologic surgery. Seventy-three percent appeared in dermatology journals. Overall, the number of publications increased linearly with time. Most of this increase was accounted for by publications in non-dermatology journals. However, there was an increase in randomized control trials over the course of the study period in dermatology journals only, while low quality-of-evidence publications accounted for most of the increase in non-dermatology journals. Over the past 10 years the field of dermatologic surgery has had a significant yearly increase in published original studies. It appears that high quality evidence on dermatologic surgery is mostly published in dermatology journals. Current trends towards evidence-based dermatology might impact future research and publications in the field of dermatologic surgery.

Mechanical Entrainment in W/O/W Emulsion Liquid Membrane

An experimental study of mechanical entrainment in W/O/W emulsions is conducted. W/O/W emulsions are stirred for various stirring times under the conditions that mechanical entrainment solely occurs, and changes in volume of the W/O emulsions and size distribution of the internal water droplets are measured. The rate of change in number of the water droplets entrained is found to be proportional to the volume fraction of W/O emulsions. Based on this result, a new model for mechanical entrainment is developed. The calculated change in W/O emulsion volume with time agrees with the observed ones except in the region near phase inversion. Then, phase inversion is discussed.

Application of optimal control theory in marketing: What is the optimal number of choices on a shopping website?

There have been some recent interests in making websites responsive to the dynamic behaviour of users. We present a method for applying the steps of optimal control theory to internet shopping platforms. The information rate is a state variable to maximise and the rate of change in number of options available to the consumer is our control variable to minimise. We apply optimal control theory to identify the optimal number of options. We specify and solve the necessary and sufficient conditions for the optimal control for a class of objective functions, which gives a nonlinear two-point boundary value problem.

Fading out of vole and predator cycles?

Northern voles and lemmings are famous for their spectacular multiannual population cycles with high amplitudes. Such cyclic vole populations in Scandinavia have shown an unexpected and marked long-term decline in density since the early 1970s, particularly with a marked shift to lower spring densities in the early 1980s. The vole decline, mainly characterized by a strongly decreased rate of change in numbers over winter, is associated with an increased occurrence of mild and wet winters brought about by a recent change in the North Atlantic Oscillation. This has led to a decrease in winter stability and has shortened the period with protective snow cover, the latter considered as an important prerequisite for the occurrence of multiannual, high-amplitude cycles in vole populations. Although the vole decline is predicted to be negative for predators' reproduction and abundance, empirical data showing this are rare. Here we show that the dynamics of a predator-prey system (Tengmalm's owl, Aegolius funereus, and voles), have in recent years gradually changed from 3-4 yr, high-amplitude cycles towards more or less annual fluctuations only.

Evaluation of the Personal Dental Services (Wave 1) for Lambeth, Southwark and Lewisham Primary Care Trusts – Part 1: Retrospective analyses of registration data and access issues

The purpose of the study was to undertake analyses of registration data for the personal dental services (PDS) of Lambeth, Southwark and Lewisham primary care trusts and relate the analyses to the PDS goal of increasing uptake of dental services. Secondary analyses of registration statistics provided by the Dental Practice Board were undertaken for both 1 years pre-PDS (October 1997 to September 1998) and post-PDS (October 1998 to March 2003) periods. Three sets of analyses were undertaken to consider different aspects of changing registrations: (1) Absolute numbers of patients registered at each time interval; (2) Rates of change in numbers of patients registered for the entire period after the introduction of PDS; and (3) Rates of change in numbers of patients registered for the most recent 3 years of available data. There was a significant increase in the numbers of children registered under capitation, post-PDS as compared to the pre-PDS level (all ages and both genders combined). Post-PDS, the rate of increase for the children was approximately one additional child per practice per month (0.96, 95% CI 0.41-1.52). Similarly there was a significant trend for increasing adults registrations over time of about two and a half adults per practice per month (2.42, 95% CI 0.90-3.95). There was no evidence of a change in registrations for children or adults in total over the most recent period of 3 years. The analysis of the absolute numbers of registered patients each month indicated that the PDS practices had more children registered than before the implementation of the PDS scheme, but not adults. Overall post-implementation there was a trend for increasing registrations in both children and adults, but the most recent data indicated a plateau effect. Further consideration of facilitators to achieve PDS goals of improved uptake of services is required, particularly as they relate to local contexts.

Population dynamics of small mammals in relation to forest age and structural habitat factors in northern Sweden

1 In northern Scandinavia there are indications of a long-term decline in the abundance of the three dominant vole species, Clethrionomys glareolus , Clethrionomys rufocanus and Microtus agrestis , since the 1970s. One explanation proposes that intensified clear-cutting has created even-aged and homogeneous forest stands with poor overall conditions for survival and reproduction of the voles. 2 We investigated the relationship between forest age and structural habitat factors and its implications for the species richness and abundance of small mammals. In particular, we assessed the population dynamics of C. glareolus , a forest-dwelling species with rather general habitat requirements . 3 Extensive snap-trapping of small mammals was conducted during 1998–2000 on 24 study sites in boreal forests in northern Sweden. Trapping was carried out along transects running from immature forests of six age classes (0–50 years) into adjacent reference sites (> 100 years). At each trapping station we recorded 14 habitat variables that were reduced to three principal components (PCs). The PCs were related to late successional traits, such as forest age and cover of tree layers (PC1), cover of tall vegetation in the field layer (PC2) and structural heterogeneity in the forest floor (PC3). 4 The species richness of small mammals, as well as the total abundance of C. glareolus , was positively influenced by tall vegetation (PC2) and structural heterogeneity (PC3) but not by late successional traits (PC1). The youngest forests had higher scores for both PC2 and PC3 compared with older forests. 5 The youngest forests also had the highest species richness and total abundance of C. glareolus . This was associated with a generally higher rate of change in numbers of C. glareolus during summer in the youngest forests compared with adjacent reference sites. In contrast, survival during winter was lower in the youngest forests. We found this result to be consistent with a source–sink scenario where young individuals, primarily born in old forest stands in early summer, migrate into younger forests to breed, but where the probabilities for winter survival are poor. 6 Our study demonstrates that both the species richness of small mammals and the population dynamics of C. glareolus are influenced to a great extent by structural habitat factors that are altered by common forest management practices in northern Sweden. In order to conserve species richness of small mammals and to minimize population fluctuations of C. glareolus in northern Scandinavia, we outline forest management practices that will provide heterogeneous environments, such as leaving logging residues on site after forest harvesting.

Spatial and Temporal Variability in Growth of Rhizophora Mangle Saplings on Coral Cays: Links with Variation in Insolation, Herbivory, and Local Sedimentation Rate

1 We used demographic growth analysis to quantify seasonal and annual patterns of shoot and root module production by Rhizophora mangle saplings growing on three coral cays in Belize, Central America. We investigated scaling relationships among root and shoot modules, leaf life-span, effects of herbivores on module and whole plant growth, and differences in growth under different sedimentation regimes. 2 Production of new shoots and aerial roots occurred seasonally. Annual peaks in solar insolation occurred in May; relative rates of change in numbers of shoot meristems and leaves, and stem length peaked one month following. Relative rate of change in numbers of aerial roots peaked one month following this shoot flush, and roots elongated primarily during the dry season. 3 Increased water depth was positively correlated with the ratio of root length to shoot length in saplings. Mean shoot growth rate was significantly lower at cays exhibiting relatively low sedimentation rates, as well as at similar locales within cays. 4 Average leaf life-span was 9 months. During an outbreak of the mangrove skipper Phocides pigmalion, insect herbivores shortened leaf life-span by increasing leaf abscission rate. Insect folivores reduced above-ground net primary production available for export to adjacent marine ecosystems by 5-20%. Up to seven-fold increases in percentage of roots bored by isopods occurred concomitantly with annual peaks in new root production. Relative elongation rate of roots decreased five-fold following isopod attack. However, whilst both insects and isopods tracked production of and consumed new modules, neither consumer contributed significantly to variance in whole-plant growth. 5 Demographic growth analysis is a powerful tool with which to predict dynamic responses of module production and whole-plant growth in response to local environmental conditions. Our analyses illustrate that growth of mangroves are sensitive to seasonal patterns of insolation, to decreasing sedimentation and to increasing water depth. Given that growth of mangrove saplings on coral cays declines significantly with sedimentation rate, persistence of these forests is unlikely if sea level in the Caribbean increases as predicted.

Variations in the contribution of transport to changes in planktonic animal abundance: a study of the flux of fish larvae in Conception Bay, Newfoundland

We investigated the magnitude of short-term variations in the flux of several species of fish larvae in Conception Bay, Newfoundland, determined the contribution of these fluxes to changes in the abundance of these species, and assessed the factors that may be causing the variations in these fluxes. The net effect of transport ranged from a daily influx of 5.8% to a daily efflux of 6.2% from the population. Short-term variations in transport were associated with variations in wind stress. The contribution of transport to variations in population abundance ranged from 12 to more than 75% of the average daily rate of change in numbers for the different species. The contribution of physical processes to estimated mortality rates is variable and can have a significant impact on the investigation and interpretation of potential biological processes (e.g., predation and starvation) influencing the survival of larval fish. We predicted that the average correction to the instantaneous mortality rate due to advection and diffusion should be proportional to A−1/2, where A is the area of system under study. This highlights the susceptibility of small systems to estimation error of mortality rates caused by short-term variations in physical forcing.