Temporal processes in prime–mask interaction: Assessing perceptual consequences of masked information

Visual backward masking is frequently used to study the temporal dynamics of visual perception. These dynamics may include the temporal features of conscious percepts, as suggested, for instance, by the asynchronous–updating model (Neumann, 1982) and perceptual–retouch theory ((Bachmann, 1994). These models predict that the perceptual latency of a visual backward mask is shorter than that of a like reference stimulus that was not preceded by a masked stimulus. The prediction has been confirmed by studies using temporal–order judgments: For certain asynchronies between mask and reference stimulus, temporal–order reversals are quite frequent (e.g. Scharlau, & Neumann, 2003a). However, it may be argued that these reversals were due to a response bias in favour of the mask rather than true temporal-perceptual effects. I introduce two measures for assessing latency effects that (1) are not prone to such a response bias, (2) allow to quantify the latency gain, and (3) extend the perceptual evidence from order reversals to duration/interval perception, that is, demonstrate that the perceived interval between a mask and a reference stimulus may be shortened as well as prolonged by the presence of a masked stimulus. Consequences for theories of visual masking such as asynchronous–updating, perceptual–retouch, and reentrant models are discussed

Quantifying the effects of temperature on mosquito and parasite traits that determine the transmission potential of human malaria

Malaria transmission is known to be strongly impacted by temperature. The current understanding of how temperature affects mosquito and parasite life history traits derives from a limited number of empirical studies. These studies, some dating back to the early part of last century, are often poorly controlled, have limited replication, explore a narrow range of temperatures, and use a mixture of parasite and mosquito species. Here, we use a single pairing of the Asian mosquito vector, An. stephensi and the human malaria parasite, P. falciparum to conduct a comprehensive evaluation of the thermal performance curves of a range of mosquito and parasite traits relevant to transmission. We show that biting rate, adult mortality rate, parasite development rate, and vector competence are temperature sensitive. Importantly, we find qualitative and quantitative differences to the assumed temperature-dependent relationships. To explore the overall implications of temperature for transmission, we first use a standard model of relative vectorial capacity. This approach suggests a temperature optimum for transmission of 29°C, with minimum and maximum temperatures of 12°C and 38°C, respectively. However, the robustness of the vectorial capacity approach is challenged by the fact that the empirical data violate several of the model's simplifying assumptions. Accordingly, we present an alternative model of relative force of infection that better captures the observed biology of the vector-parasite interaction. This model suggests a temperature optimum for transmission of 26°C, with a minimum and maximum of 17°C and 35°C, respectively. The differences between the models lead to potentially divergent predictions for the potential impacts of current and future climate change on malaria transmission. The study provides a framework for more detailed, system-specific studies that are essential to develop an improved understanding on the effects of temperature on malaria transmission

Rethinking the extrinsic incubation period of malaria parasites

The time it takes for malaria parasites to develop within a mosquito, and become transmissible, is known as the extrinsic incubation period, or EIP. EIP is a key parameter influencing transmission intensity as it combines with mosquito mortality rate and competence to determine the number of mosquitoes that ultimately become infectious. In spite of its epidemiological significance, data on EIP are scant. Current approaches to estimate EIP are largely based on temperature-dependent models developed from data collected on parasite development within a single mosquito species in the 1930s. These models assume that the only factor affecting EIP is mean environmental temperature. Here, we review evidence to suggest that in addition to mean temperature, EIP is likely influenced by genetic diversity of the vector, diversity of the parasite, and variation in a range of biotic and abiotic factors that affect mosquito condition. We further demonstrate that the classic approach of measuring EIP as the time at which mosquitoes first become infectious likely misrepresents EIP for a mosquito population. We argue for a better understanding of EIP to improve models of transmission, refine predictions of the possible impacts of climate change, and determine the potential evolutionary responses of malaria parasites to current and future mosquito control tools

Dementia care in Israel: top down and bottom up processes

Abstract Dementia is one of the main causes of disability among older adults and is viewed as one of the most distressing and devastating of conditions. Dementia has a profound impact on those who suffer from the disease and on their family caregivers. In this article, we describe the added benefit of implementing top-down and bottom-up strategies in the process of influencing and developing healthcare services. We use Israel as an example to argue that breakthroughs in care implementation and development of services are more likely to occur when there is a convergence of top-down and bottom-up processes. In the first section of the article, we present the top-down plans, initiated to address the needs of people with dementia and their families. In the second section, we present examples of bottom-up projects that developed in Israel before and after the top-down plans were initiated. In the third section, we contend that it is the combination of these top-down and bottom-up strategies that led to a breakthrough and the expansion of services for people with dementia and their families, and we argue that the Israeli case study is applicable to other health systems

Home hospice for older people with advanced dementia: a pilot project

Abstract Background Dementia is a terminal illness making the palliative and hospice approach to care appropriate for older people with advanced dementia. Objective To examine clinical and health services outcomes of a quality improvement pilot project to provide home hospice care for older people with advanced dementia. Study design Twenty older people with advanced dementia being treated in the Maccabi Healthcare Services homecare program, received home hospice care as an extension of their usual care for 6–7 months (or until they died) from a multidisciplinary team who were available 24/7. Family members were interviewed using validated questionnaires about symptom management, satisfaction with care, and caregiver burden. Hospitalizations prevented and medications discontinued, were determined by medical record review and team consensus. Findings The findings are based on 112 months of care with an average of 5.6 (SD 1.6) months per participant. The participants were on average 83.5 (SD 8.6) years old, 70% women, in homecare for 2.8 (SD 2.0) years, had dementia for 5.6 (SD 3.6) years with multiple comorbidities, and had been hospitalized for an average of 14.0 (SD 18.1) days in the year prior to the project. Four patients were fed via artificial nutrition. During the pilot project, 4 patients died, 2 patients withdrew, 1 patient was transferred to a nursing home and 13 returned to their usual homecare program. The home hospice program lead to significant (p < 0.001)improvement in: symptom management (score of 33.8 on admission on the Volicer symptom management scale increased to 38.3 on discharge), in satisfaction with care (27.5 to 35.3,), and a significant decline in caregiver burden (12.1 to 1.4 on the Zarit Burden index). There were five hospitalizations, and 33 hospitalizations prevented, and an average of 2.1(SD 1.4) medications discontinued per participant. Family members reported that the professionalism and 24/7 availability of the staff provided the added value of the program. Conclusions This pilot quality improvement project suggests that home hospice care for older people with advanced dementia can improve symptom management and caregiver satisfaction, while decreasing caregiver burden, preventing hospitalizations and discontinuing unnecessary medications. Identifying older people with advanced dementia with a 6 month prognosis remains a major challenge

ThinkCascades : a tool for identifying clinically important prescribing cascades affecting older people

Background and Objective Prescribing cascades occur when a drug is prescribed to manage side effects of another drug, typically when a side effect is misinterpreted as a new condition. A consensus list of clinically important prescribing cascades that adversely affect older persons’ health (i.e., where risks of the prescribing cascade usually exceed benefits) was developed to help identify, prevent, and manage prescribing cascades. Methods Three rounds of a modified Delphi process were conducted with a multidisciplinary panel of 38 clinicians from six countries with expertise in geriatric pharmacotherapy. The clinical importance of 139 prescribing cascades was assessed in Round 1. Cascades highly rated by ≥ 70% of panelists were included in subsequent rounds. Factors influencing ratings in Rounds 1 and 3 were categorized. After three Delphi rounds, highly rated prescribing cascades were reviewed by the study team to determine the final list of clinically important cascades consistent with potentially inappropriate prescribing. Results After three rounds, 13 prescribing cascades were highly rated by panelists. Following a study team review, the final tool includes nine clinically important prescribing cascades consistent with potentially inappropriate prescribing. Panelists reported that their ratings were influenced by many factors (e.g., how commonly they encountered the medications involved and the cascade itself, the severity of side effects, availability of alternatives). The relative importance of these factors in determining clinical importance varied by panelist. Conclusions A nine-item consensus-based list of clinically important prescribing cascades, representing potentially inappropriate prescribing, was developed. Panelists’ decisions about what constituted a clinically important prescribing cascade were multi-factorial. This tool not only raises awareness about these cascades but will also help clinicians recognize these and other important prescribing cascades. This list contributes to the prevention and management of polypharmacy and medication-related harm in older people