Lack Of Knowledge Research Articles

Application of best estimate plus uncertainty in review of research reactor safety analysis

To construct and operate a nuclear research reactor, the licensee is required to obtain the authorization from the regulatory body. One of the tasks of the regulatory authority is to verify that the safety analysis fulfils safety requirements. Historically, the compliance with safety requirements was assessed using a deterministic approach and conservative assumptions. This provides sufficient safety margins with respect to the licensing limits on boundary and operational conditions. Conservative assumptions were introduced into safety analysis to account for the uncertainty associated with lack of knowledge. With the introduction of best estimate computational tools, safety analyses are usually carried out using the best estimate approach. Results of such analyses can be accepted by the regulatory authority only if appropriate uncertainty evaluation is carried out. Best estimate computer codes are capable of providing more realistic information on the status of the plant, allowing the prediction of real safety margins. The best estimate plus uncertainty approach has proven to be reliable and viable of supplying realistic results if all conditions are carefully followed. This paper, therefore, presents this concept and its possible application to research reactor safety analysis. The aim of the paper is to investigate the unprotected loss-of-flow transients "core blockage" of a miniature neutron source research reactor by applying best estimate plus uncertainty methodology. The results of our calculations show that the temperatures in the core are within the safety limits and do not pose any significant threat to the reactor, as far as the melting of the cladding is concerned. The work also discusses the methodology of the best estimate plus uncertainty approach when applied to the safety analysis of research reactors for licensing purposes.

Awareness and Adoption of Paddy Farmers in Buttala Sri Lanka to Golden Rules of Pesticide Usage

Pesticides are widely used in agricultural production to prevent or control pests, diseases,weeds and other plant pathogens in an effort to reduce or eliminate yield losses and maintainhigh produce quality. There is a higher risk in pesticide usage due to hazardous nature ofthem; hence, safety measures should have practiced to minimize the threats. Especially inPaddy cultivation, various types of pesticides were applied during its various growing stagesas from the seedling to harvest. The objective of the study was to investigate the awarenessand adoption on “Golden Rules” which are (1) exercise caution at all times (2) carefulreading and understanding of label before use (3) practicing good personal hygiene (4) takecare of and maintain application equipment and (5) wear appropriate personal protectiveclothing and equipment, in the area of Buttala, Sri Lanka at three levels as “High””Moderate” and “Low”. A field survey which based on pre tested questionnaire was carriedout by using randomly selected 50 Paddy farmers without considering their age classes,education and economic status etc. to find out the awareness and adoption to “Golden Rules”in five operations (in the operations of pesticide buying, transportation, storage, applicationand disposal). Survey results revealed that the farmers of Buttala did not aware on “Goldenrules” and their adherence to “Golden Rules” is not satisfactory. Moreover, “Moderate” levelof awareness and adoption on the processes of buying (52, 48%) and storage (51, 52%) but“Low” awareness and adoption on transportation (51, 52%), application (48, 48%) anddisposal (52%, 50%) seen from total number of farmers (n=50). The risk of contaminationwas high due to careless transportation, application and disposal because of “Low” awarenessand adoption for those processes therefore immediate awareness programs are required.According to survey findings the pesticides were applied heavily because of the lack ofknowledge and elevated pest and disease problems, therefore there was a threat toenvironment mainly from application and disposal by contaminating water sources of thearea. Promoting of extension services, farmer credit facilities to buy safe equipments,directing farmers towards integrated pest management and activate regulations on pesticideusage are needed to protect public from hazardous agrochemicals. Furthermore, this is amatter of concern to overcome the hazardous problem of pesticides use before it isecologically and socially getting worst in the future.

Resolving the Conflict between Mining and Sustainability

Mining is essential for human health and prosperity, and is increasing as the global populationgrows. The need for minerals appears to conflict with what is commonly understood as ‘sustainability’,as geological resources are non-renewable on a human timescale. However, the Brundtland definition of sustainability includes the concept of ‘needs’, implying that there has to be a balanced approach thatconsiders poverty alleviation. It identifies the three pillars of sustainability: economic, social and environmental.In the UK, mining has a legacy extending back over 6000 years. The approach taken to sustainability will be illustrated by 3 examples from northern England. In the 18thand 19thcenturies, the London Lead Company was directed by members of the Religious Society of Friends, and hadsocial sustainability as a high priority, building a village with facilities to promote physical, mental and spiritual healthamongst the mining community. The legacy of this company’s mining operations on river water pollution is currently a major problem, reflecting its lackof knowledge of geochemistry.Potash mining started in North Yorkshire in the 1960s, and now there are plans for a new potash mine within the North York Moors National Park.Over 1 km deep, the new mine is planned to be as invisible as possible. Open pit coal mining takes place as part of aconstruction operation in city centreNewcastle, and in nearbyrural locations. Operators take great care to minimize their impact on local populations, adaptingequipment and making sure operations are timed to minimize disturbance.In the UK, one key characteristic of a successful mining operation is that it engages in dialogue with the local community.It is important to involve the community right from the start of planning a mine, even before its location has been finalized. Operators typically have a community fund, and this can be approached by local people to pay for resources that benefit the community, such as sports equipment and facilities. Mining companies need to have a clear plan for restoration, with dates, and some take the opportunity to plan major works of public art as a way of enriching the community with a legacy that can generate income through tourism.

Contribution of Remote Sensing and Geographic Information System to Identify Potential Areas of Groundwater in the Department of M'Bahiakro (Central-East of Côte d'Ivoire)

This study concerns an area located at central -east of CUte d'Ivoire and constituted by fractured crystalline and metamorphic rocks. In this area, problems of drinking water supply exist because of overpopulati on and lack ofknowledges about groundwater prospection.This study aims to highlight hydrogeological potentiality areas where drilling can provide a large discharge.Database is constituted by technical data from drillings and satellite images of Landsat ETM+. Remote sensing tools, multi-criteria analysis and geographic information systems (GIS) are used in this study. Theresults indicate that water resources are available in this area. GIS enabled to elaborate thematic maps of

A robust CRE-based approach for model updating using in situ measurements

This paper presents a systematic approach for comparing a numerical model to test results performed in situ on a structure with time-dependent behavior. A crucial issue for an engineer is to be able to assess the quality of models, based on a series of measurements. Dealing with in situ measurements as experimental reference for model updating involves two major difficulties: the excitations can be multiple and affected by large disturbances. The validation process we propose is based on the mechanical concept of Constitutive Relation Error (CRE) and aims at reducing the Lack Of Knowledge (LOK) attached to both the excitation forces and the parameters of the numerical model. The updated values can be computed inside confidence intervals that correspond to the lower contours of the CRE-based residual to minimize.The proposed method will be illustrated with a numerical example taken from the aerospace industry and applied for correcting a simple Ariane 5 model by comparison with flight measurements.

Printed guide improves knowledge of curative, palliative, and hospice care among women with metastatic breast cancer

To the Editor:Self-management is the ability of patients along with familymembers to manage physical, psychosocial, and spiritualconsequences of their health condition(s) [1, 2]. Breastcancer survivors want to self-manage [3–7]; however, lackof knowledge about care options—curative, palliative, andhospice care—is an obstacle [8, 9]. Confusion arises becausecare options are not distinct; palliative care can be providedconcurrently with curative care and is part of hospice care.Understanding care options is important because self-management decisions vary by care option. We report resultsof a pilot study testing a self-management intervention forbreast cancer survivors designed to improve knowledge ofcare options and to facilitate self-management by improvingdesiretoself-manage,communicationskills,andself-efficacy,and reducing anxiety, depression, and uncertainty. Self-management is critical for metastatic breast cancer survivorswho may spend years undergoing arduous treatments,weighing choices, and negotiating transitions. Our interven-tion offers support for these challenges. The intervention,“Managing Cancer Care: A Personal Guide”, consists ofseven printed modules of four pages each: “Managing YourSymptoms,”“ManagingYourCareandSettingGoals,”“CareOptions,”“Talking With Health Care Providers,”“Talkingwith Family and Friends,”“Managing Transitions,” and“Acting Confidently During Uncertainty.” Content was basedon our earlier studies of patients’ self-management [3, 10],with input from oncology staff and patients. Modules includepersonalized worksheets, “conversation starters”, and links toadditional resources. This intervention provides patients withinformation, tools, and empowerment to self-manage withfamily members and clinicians, and we believe that this isthe first study to focus on integrating knowledge of careoptions into self-management.This one-group, pre-post test study was conducted over2 months, and was approved by the Yale University HumanInvestigationCommittee.Eligibleparticipantswererecruitedata breast clinic January–May 2010 and included English-speaking women aged 21+, with metastatic breast cancer, anda prognosis of ≥3 months. Potential participants wereapproachedbytheirchemotherapynurse.Ifinterested,researchstaff explained the study and obtained consent. Following pre-test data collection, participants were oriented to all modules.After 1 month, participants were phoned to assess use of theguide,answerquestions,andschedulepost-testdatacollection,including an interview, 1 month later. Participants were askedto rate each module and the set on usefulness and appearance(1 = least; 10 = most) and to provide feedback.Data collection included demographic and clinical data,and six outcome measures. The Knowledge of Care Optionstest (KOCO), content validated in this study, uses a true–false format to assess knowledge of care options [8]. Anadapted Control Preferences Scale (CPS) was used to mea-sure preferred and actual roles in self-management [11]. TheMedical Communication Competence Scale [12] was usedto measure medical communication. Anxiety and depressionwere assessed with the Hospital Anxiety and DepressionScale [13]. Uncertainty was measured using the Uncertaintyin Illness Scale [14]. The Chronic Disease Self-EfficacyScale (CDSE) [15] was used to measure self-efficacy.Descriptive statistics were calculated for demographic andclinical data. Signed Rank Tests investigated change in out-come measures. Cohen’s effect sizes were calculated withmean differences and standard deviations. The WilcoxonRank Sum test was used to examine differences in changedscores on outcome measures between dichotomized demo-graphic groups. Descriptive statistics were calculated for par-ticipants’ ratings of the guide. Content analysis was used toexamine responses to interview questions.

Demand Forecasting for Domestic Air Transportation in Turkey

introduction Patients have the right to influence the care they receive, but their wish to participate in care decision-making is unclear. Aim This study investigates whether participation in nursing documentation influences patient participation in care decision-making, mastery, self-esteem, empowerment and depressive feelings among adult in-patients with chronic disease. Materials and Methodology Adult patients (n=39) with chronic diseases were randomized. The intervention group participated in nursing documentation. Upon departure, patients filled in questionnaires about participation in care decision-making, mastery, self-esteem, empowerment and depressive feelings. Results The majority of the patients preferred a collaborative or passive role regarding care decision-making. Lack of knowledge was one reason for non-participation. Having been diagnosed more than five years previously meant stronger empowerment. Conclusion It is a challenge for nurses to find strategies to assess patients’ wishes regarding participation in care decision-making. Nurses must support patients’ knowledge of their disease and empowerment.

Reconstructing the history of euxinia in a coastal sea

Areas of the coastal ocean where oxygen is low or absent in bottom waters, so-called dead zones, are expanding worldwide (Diaz and Rosenberg, 2008). Increased inputs of nutrients from land are enhancing algal blooms, and the sinking of this organic matter to the seafl oor and subsequent decay leads to a high oxygen demand in bottom waters. Depending on the physical characteristics of the coastal system, this may initiate periodic or permanent water column anoxia and euxinia, with the latter term implying the presence of free sulfi de (Kemp et al., 2009). Global warming is expected to exacerbate the situation, through its effects on oxygen solubility and water column stratifi cation. In many modern coastal systems, anthropogenic changes are superimposed on natural variation and lack of knowledge of such variation makes the prediction of future changes in water column oxygen challenging (e.g., Grantham et al., 2004). That natural drivers alone can be the cause of widespread coastal anoxia is evident from studies of greenhouse periods in Earth’s past, including the oceanic anoxic events of the Cretaceous and Toarcian (Jenkyns, 2010).

EVOLUTIONARY ORIGIN OF A FUNCTIONAL GONADOTROPIN IN THE PITUITARY OF THE MOST PRIMITIVE VERTEBRATE, HAGFISH

Hagfish, which lack both jaws and vertebrae, are considered themost primitive vertebrate known, living or extinct. Hagfish havelong been the enigma of vertebrate evolution not only becauseof their evolutionary position, but also because of our lack ofknowledge on fundamental processes. Key elements of the re-productive endocrine system in hagfish have yet to be elucidated.Here, the presence and identity of a functional glycoprotein hor-mone (GPH) have been elucidated from the brown hagfish Para-myxine atami. The hagfish GPH consists of two subunits, α and β,which are synthesized and colocalized in the same cells of theadenohypophysis. The cellularand transcriptional activitiesof hag-fish GPHα and -β were significantly correlated with the develop-mental stages of the gonad. The purified native GPH induced thereleaseofgonadalsexsteroidsinvitro.Fromourphylogeneticanal-ysis, we propose that ancestral glycoprotein α-subunit 2 (GPA2)and β-subunit 5 (GPB5) gave rise to GPHα and GPHβ of the verte-brate glycoprotein hormone family, respectively. The identifiedhagfishGPHαand-βsubunitsappeartobethetypicalgnathostomeGPHαand-βsubunitsbasedonthesequenceandphylogeneticanal-yses.WehypothesizethattheidentityofasinglefunctionalGPHofthehagfish,hagfishGTH,providescriticalevidencefortheexistenceof a pituitary-gonadal system in the earliest divergent vertebratethat likely evolved from an ancestral, prevertebrate exclusivelyneuroendocrine mechanism by gradual emergence of a previouslyundescribed control level, the pituitary, which is not found inthe Protochordates.

Evolutionary Origin of a Functional Gonadotropin in the Pituitary of the most Primitive Vertebrate, Hagfish

Hagfish, which lack both jaws and vertebrae, are considered themost primitive vertebrate known, living or extinct. Hagfish havelong been the enigma of vertebrate evolution not only becauseof their evolutionary position, but also because of our lack ofknowledge on fundamental processes. Key elements of the re-productive endocrine system in hagfish have yet to be elucidated.Here, the presence and identity of a functional glycoprotein hor-mone (GPH) have been elucidated from the brown hagfish Para-myxine atami. The hagfish GPH consists of two subunits, α and β,which are synthesized and colocalized in the same cells of theadenohypophysis. The cellularand transcriptional activitiesof hag-fish GPHα and -β were significantly correlated with the develop-mental stages of the gonad. The purified native GPH induced thereleaseofgonadalsexsteroidsinvitro.Fromourphylogeneticanal-ysis, we propose that ancestral glycoprotein α-subunit 2 (GPA2)and β-subunit 5 (GPB5) gave rise to GPHα and GPHβ of the verte-brate glycoprotein hormone family, respectively. The identifiedhagfishGPHαand-βsubunitsappeartobethetypicalgnathostomeGPHαand-βsubunitsbasedonthesequenceandphylogeneticanal-yses.WehypothesizethattheidentityofasinglefunctionalGPHofthehagfish,hagfishGTH,providescriticalevidencefortheexistenceof a pituitary-gonadal system in the earliest divergent vertebratethat likely evolved from an ancestral, prevertebrate exclusivelyneuroendocrine mechanism by gradual emergence of a previouslyundescribed control level, the pituitary, which is not found inthe Protochordates.

Análise dos parques naturais de Canela/RS com ênfase nas atividades de educação

O presente trabalho teve como objetivo analisar as atividades de Educação Ambiental realizadas nos Parques Naturais do município de Canela/RS, incluindo sua relação com o Turismo Sustentável. Deste modo, inicialmente identificaram-se os parques com características naturais relevantes e elaborou-se um questionário que foi virtualmente respondido pelos seus administradores. O questionário foi composto por 15 questões que objetivavam a avaliar questões amplas e restritas sobre a área dos parques como: sua localização e estruturas, administração, público, aspectos de conservação, relação social e práticas de Educação Ambiental. Dos 17 parques naturais relacionados, 10 responderam ao questionário. A partir deste trabalho verificouse que existe um grande despreparo em relação à administração dos parques sobre sua conservação e gestão. Evidencia-se também o desconhecimento em relação aos fatores abióticos, bióticos e socioeconômicos dos parques, os quais, a maioria, não possui plano de manejo. Há um profundo despreparo dos administradores em relação aos conceitos de Turismo Sustentável e às próprias práticas de Educação Ambiental, fazendo uso desses termos indiscriminadamente como marketing-verde.

The Lack-Of-Knowledge (LOK) theory for linear buckling analysis problems

As an extension of safety factors, the Lack-Of-Knowledge theory (LOK) is an answer to model validation issues in structural mechanics. The approach is based on a decomposition of the model into several substructures and a global description of uncertainties at that level through basic LOK on stiffness matrices. These uncertainties are introduced using intervals with probabilistic bounds. The theory then enables to propagate uncertainties on a quantity of interest. Previous work presented results for linear static and dynamic problems. We introduce in this paper a propagation method of the basic LOKs on buckling loads of structures and present its application on academical and industrial examples.

Cyanotoxins: A dermatological problem

Cyanobacteria (blue-green algae), that are common inhabitants of water and terrestrial environments throughout the world, produce a broad spectrum of secondary metabolites - biologically active products that could be toxic (cyano?toxins). Scientific literature data unequivocally showed adverse effects of cyanotoxins on animal and human health, above all their hepatotoxic and neurotoxic activities. However, the cutaneous adverse effects of cyanobacteria and their cyanotoxins are often under-diagnosed, misdiagnosed or under reported together with a long-standing lack of knowledge about it, not only amongst primary healthcare providers, but also amongst dermatologists. The seaweed dermatitis is the first described cutaneous adverse effect that occurred after contact with marine waters in cyanobac?terial toxic bloom condition. This acute irritant dermatitis was connected with the benthic marine filamentous cyano?bacterium Lyngbya majuscula (Gomont) and its toxins (debromoaplysiatoxin, aplysiatoxin and lyngbyatoxin A). Apart from irritant cutaneous adverse effects, the hypersensitivity immune responses were reported as well, i.e. allergic con?tact dermatitis due to cylindrospermopsin from Cylindrospermopsis raciborski. Aside from direct or indirect (airborne dermatitis) local effects of cyanotoxins on the skin and/or mucous membranes, a severe systemic manifestations were also diagnosed, such as hay fever, asthma and generalized urticarial rash, as well as ocular symptoms and signs e.g., itchy edematous eyelids associated with conjunctivitis. Potentially toxic cyanobacteria and their toxins are present in water resources of the Republic of Serbia, which means that an adequate, relevant and more-coordinated monitoring of all water environments is crucial for preventing human exposure to cyanobacteria and their toxins. A significant role in all of these could and should be taken by dermatologists, above all in the identification of the cyanobacterial adverse effect on skin and mucous membranes, as well as in diagnostic allergy testing.

Destination Marketing Through Film Tourism: A Study on Western Orissa

Film tourism is a growing phenomenon worldwide, fueled by both the growth of the entertainment industry and the increase in international travel model for exploiting film tourism marketing opportunities. Tourism destination marketing is now widely recognized as an essential component in the management of destinations. In harmony with the general marketing literature, which understands marketing as a management tool, some researchers understand destination marketing as a form of 'market-oriented strategic planning' and hence as a strategic approach to place development rather than a promotional tool.Tourists today are more experienced and looking for new destinations and new experience. In the tourism industry, there has been a growing phenomenon that tourists visit destinations featured through films which are not directly related to DMOs' tourism promotion. This is a new form of cultural tourism called film-induced tourism which still receives little attention from both academic and practitioners due to the lack ofknowledge and understanding on the benefits of film on tourism. Recent research suggests that films can have strong influence on tourist decision-making and films do not only provide short-term tourism revenue but long-term prosperify to the destination. The primary focus of this article is to provide a theoretical insight into the relationship between films induced tourism and destination imagery, which in turn can be used to market Western Orissa.

On lack-of-knowledge theory in structural mechanics

Today, the validation of complex structural models – i.e. the assessment of their quality compared to an experimental reference – remains a major issue. Strictly speaking, the validation problem consists in comparing the response of the numerical model (whether deterministic or stochastic) with complete reality. A first answer to this problem, using Lack-Of-Knowledge (LOK) theory, was introduced at LMT-Cachan. This theory is an attempt to “model the unknown” by taking all the sources of uncertainties, including modeling errors, into account through the concept of basic LOKs. In this article, we introduce basic LOKs associated with both the amplitudes and directions of excitations. These basic LOKs are propagated rigorously throughout the mechanical model in order to determine intervals (with stochastic bounds) within which lies a given quantity of interest (stress or displacement). Then, we introduce a strategy for the reduction of lack of knowledge, which we illustrate through an academic example.

Drug Compliance Among Hypertensive Patients; an Area Based Study

Aim: To estimate the compliance rate, associated factors, status of blood pressure control and reasons for non-compliance among patients on treatment for hypertension. Methods: Patients attending the hypertension clinic of Hadiya center were followed up for at least 6 months. They are labeled as uncontrolled if the mean of three consecutive measures of systolic blood pressure was ≥140 mm Hg and /or mean diastolic blood pressure was ≥90 mmHg.Hadiya family practice center in Ahmadi health district in Kuwait. One hundred fifty four hypertensive patients were included in the study.Compliance, demographic variables, duration of hypertension, presence of complications, patient knowledge of hypertension, status of blood pressure control and reasons for non-compliance. Results: Out of 154 subjects recruited, 132 completed follow-up of 6 months, of whom 84 (64%) had uncontrolled hypertension. Seventeen percent of the uncontrolled hypertensives were non-compliant by pill count as compared to 2% of the controlled hypertensives (p<0.05). The compliance rate was 88.6%. Non- compliance was associated with lack of knowledge about hypertension (p<0.05). There was no statistically significant difference in the demographic variables, duration of hypertension and presence of complication rates between compliant and non-compliant hypertensives. Reasons for non-compliance included forgetfulness, drugs side effects, shortage of drugs, poly pharmacy and the asymptomatic nature of hypertension.. Conclusion: The compliance rate was high in this study and was accompanied by inadequate blood pressure control among non-compliant subjects. Non- compliance was associated with lack of knowledge about hypertension. This calls for increasing the patient’s awareness of the diagnosis and the need for compliance with medication to achieve control of hypertension in the community.

Key sources of imprecision in radiological emergency response assessments

In the first few hours after an accidental release of radioactivity to the atmosphere it islikely that limited measurements of radioactivity in the environment will be available onwhich to make decisions concerning protection measures and radiation monitoringactivities, and that monitoring data will be supplemented by the predictions of models.There will be imprecision associated with these predictions, partly resulting from lack ofknowledge (for example, about the nature of the release and the actual stateof the weather), partly due to imprecision in the models themselves and partlydue to intrinsic imprecision associated with the accuracy of the measurements.This study considers the relative importance of the key parameters influencingassessment imprecision and discusses the implications for emergency response systems.

Forty Years after the War of June 1967

On 5 June 2007, the fortieth anniversary of the Six Day War and the Israelioccupation of Palestine, the Kay Spiritual Life Center hosted “Forty Yearsafter the War of June 1967: Is Israeli-Palestinian Peace Possible?” on thecampus of American University in Washington, DC. This panel featuredYuval Rabin (son of former Prime Minister Yitzhak Rabin; governing board,the Rabin Center), Amjad Atallah (president, Strategic Assessments Initiative),Aaron David Miller (public policy scholar, the Woodrow WilsonCenter), and Ziad Asali (president, American Task Force on Palestine; panelchair).Rabin opened by describing the Six Day War as “a war of our existence.”He discussed the importance of the Camp David, Oslo, and other negotiationsand then talked about Israel’s 1967 victory. After stating that both sidesin this continued conflict have faced hardship, he also mentioned the lack ofknowledge involving certain issues.Atallah explained how Americans are bogged down with this conflict’stechnicalities, such as the number of checkpoints, which causes them to neglectthe bigger picture. He pointed out that on 29 November 1947, the UnitedNations General Assembly passed a resolution (33 to 13) recommending thatPalestine be partitioned into two states, with over half of the land going to theJews and the rest going to the Palestinians. By May 1948, according to theUnited Nations and the State Department, 350,000 Palestinians had beenexpelled from their homes. The Arab states declared war on Israel and, outnumberedand under-equipped, 400,000 more Palestinians were expelled. Atthe time, the Israelis accepted partition and the Arabs rejected the plan. Heexplained that the Israelis rushed to the Sinai Peninsula and the Jordan riverand fully understood the rules of diplomacy. This resulted in Jordan takingover what is now the West Bank. In the course of the Six Day War, another600,000 Palestinians were displaced, some for the second time ...

Improving End-of-Life Care for Older Adults: An International Challenge

ND-OF-LIFE care, a dimension of care that is providedcommonly within the context of both geriatric andpalliative care, is now receiving more attention as an area ofstudy. Despite a growing body of literature addressing careat the end of life, there is still little regarding how this care isprovided for many geriatric populations. Two studies in thepresent issue of the Journal, though reflective of the country-specific organization of health and end-of-life care,demonstrate the international challenges to be faced inproviding optimal end-of-life care for older adults.Menec and colleagues (1) concern themselves with healthservices use for older Manitobans nearing the end of life.The researchers demonstrate substantial differences in carepatterns among younger-old (65–74 years), old (75–84), andolder-old ( 85) age groups. Perhaps not surprisingly,a much greater proportion of older-old deaths (nearly half)occur in long-term care institutions; however, also in thatoldest group, deaths that occur at home are less likely tooccur with the provision of in-home care. Further, the oddsof hospital use at 1 month and 6 months prior to death arelower in the oldest-old category versus the middle group,and intensive care unit use for the same period declinessignificantly by age grouping. Among all older adults, fewerthan 30% of deaths occurred in the home, the setting wheremany patients state they would prefer to die.The fact that almost one half of all older adults in the 85þage range die in long-term care settings highlights the needfor improved palliative care in nursing homes. As noted byTeno and others, nursing homes have been among theslowest to adopt palliative care approaches to dying patients(1–3). Long-term care settings are often hindered by lack ofknowledge regarding palliative care interventions at the endof life and a more rehabilitative orientation toward care,which may no longer be appropriate for these patients. Thisstudy provides compelling data on the large numbers ofolder adults in long-term facilities who could benefit fromgood end-of-life care.De Gendt and colleagues (4) take a more granular look atdecision-making and advance care-planning practices inacute geriatrics wards in Belgium. Their finding thatapproximately one fifth of patients have do-not-resuscitate(DNR) orders is similar to an older rate reported for anAmerican ward (5), but much lower than the prevalence ofDNR orders on Dutch geriatrics wards (6,7). The research-ers focus on the process by which DNR status is obtainedand observe marked variation in practice patterns forprocuring DNR orders. Even in an acute geriatric setting,the bulk of orders appeared to be obtained very late in thecourse of disease with little use of advance directives, orconsultation with patients’ general practitioners or thepatients themselves. While head nurses were very frequentlyconsulted prior to writing the order, geriatricians tended tomake the decision during daily rounds rather than in weeklyinterdisciplinary team meetings. Of greatest concern was therelative infrequency of patient and family involvement inthese treatment decisions.Both studies highlight gaps in current end-of-life care forolder adults. The absolute number of older adults receivingend-of-life care in institutional settings (hospital or nursinghome) emphasizes the need for additional palliative caretraining. The continued disconnect between treatmentdecisions at the end of life, advance care planning, andpatient autonomy suggest opportunities for improvement insystems-based practice. Indeed, in De Gendt’s cohort,simple practices such as having a DNR policy substantiallyimproved information about DNR status.The settings of long-term care and community-basedadvanced-illness care serve as natural intersection points forpalliative care and geriatric care providers to collaborate andinfluence policy for better care for older patients at the end oflife. Menec and De Gendt’s studies show us that, as providerswithin existing systems of care, we have a long way to go toproviding optimal end-of-life care to aged adults.

On a strategy for the reduction of the lack of knowledge (LOK) in model validation

Today, the quantification of the quality of a dynamic structural model remains a major issue, and the number of methods being devised in order to validate a model by comparison with an experimental reference keeps increasing. This paper presents a theory based on the concept of lack of knowledge, which consists in globalizing the various sources of errors on the substructure level by means of a scalar internal variable, called the LOK variable, defined over an interval whose upper and lower bounds follow probabilistic laws. These intervals, which are defined for each substructure, are then propagated rigorously throughout the mechanical model in order to determine intervals with stochastic bounds within which lies a given quantity of interest defined over the whole structure. Then, a general strategy for the reduction of the lack of knowledge is discussed and applied to academic examples as well as industrial cases.