Atypical thymomas with squamoid and spindle cell features: clinicopathologic, immunohistochemical and molecular genetic study of 120 cases with long-term follow-up.

Thymomas are rare tumors characterized by a broad range of morphologic appearances that can sometimes give rise to difficulties for classification. We have studied a series of 120 thymoma patients in whom the tumors were characterized by sheets of atypical epithelial cells with squamoid and/or spindle cell features. They occurred in 63 men and 57 women and presented as a discrete mass in the anterior mediastinum measuring 2-23 cm (mean: 8.2 cm). Patients' ages ranged from 14 to 86 years (mean: 57.8) and most had symptoms referable to a mass lesion. 20 patients had myasthenia gravis or other autoimmune disorder. 76 cases were characterized by a predominant population of round to polygonal tumor cells while 32 cases were characterized by atypical oval or spindle cells. 12 cases showed mixed features and 16 cases showed the development of thymic carcinoma arising from thymoma. All cases were positive for p40/p63 and cytokeratin AE1/AE3. 23 cases were positive for CD5 (25%), and 13 for CD117 (14%). MIB1 showed a significant increase in proliferative activity (mean = 11.6%). Next generation sequencing in 47 cases did not disclose any variants amenable to current targeted therapies. Clinical follow up ranging from 2 to 29 years showed a progressive increase in aggressive behavior and fatality rate with advancing stage. Overall survival was 87% at 5 years, 67% at 10 years, and 23% at 20 years. Completeness of resection and staging were the most significant parameters for survival. The more aggressive tumors followed a protracted clinical course with multiple recurrences and metastases over a long period of time (mean = 19.8 years from time of initial relapse to death). Atypical thymomas are a distinct category of thymic epithelial neoplasm characterized by a slowly progressive clinical course with increased potential for metastases, transformation to a higher-grade malignancy, and fatal outcome in some cases.

Evaluation of a workplace suicide prevention program in the Australian manufacturing industry: protocol for a cluster-randomised trial of MATES in manufacturing.

Males are at higher risk of death by suicide than females in Australia, and among men, blue-collar males are at higher risk compared to other working males. In response, MATES in Construction developed a workplace suicide prevention program for the construction sector in 2007 that has been widely implemented in Australia. In the current project, this program is being adapted and trialled in the manufacturing sector. The common aims of MATES programs are to improve suicide prevention literacy, help-seeking intentions, and helping behaviours. The program will be evaluated using a cluster randomised-controlled trial design with waitlist controls across up to 12 manufacturing worksites in Australia. We hypothesise that after 8 months of the MATES in Manufacturing program, there will be significantly greater improvements in help-seeking intentions (primary outcome) compared to waitlist controls. The project is led by Deakin University in collaboration with the University of Melbourne, and in partnership with MATES in Construction and a joint labour-management Steering Group.Trial registration: The trial was registered retrospectively with the Australian New Zealand Clinical Trials Registry on 25 January 2022 (ACTRN12622000122752).Protocol version: 2.0, November 2022.

Protocol for a randomised controlled trial evaluating the effectiveness of a CBT-based smartphone application for improving mental health outcomes in adolescents: the MobiliseMe study.

BACKGROUND: Depression is a leading cause of disability in adolescents, however few receive evidence-based treatment. Despite having the potential to overcome barriers to treatment uptake and adherence, there are very few CBT-based smartphone apps for adolescents. To address this gap, we developed ClearlyMe®, a self-guided CBT smartphone app for adolescent depression and anxiety. ClearlyMe® consists of 37 brief lessons containing core CBT elements, accessed either individually or as part of a 'collection'. Here, we describe the protocol for a randomised controlled trial aiming to evaluate the effect of ClearlyMe® on depressive symptoms and secondary outcomes, including engagement, anxiety and wellbeing, when delivered with and without guided support compared to an attention matched control. METHODS: We aim to recruit 489 adolescents aged 12-17 years with mild to moderately-severe depressive symptoms. Participants will be screened for inclusion, complete the baseline assessment and are then randomly allocated to receive ClearlyMe® (self-directed use), ClearlyMe® with guided SMS support (guided use) or digital psychoeducation (attention-matched control). Depressive symptoms and secondary outcomes will be assessed at 6-weeks (primary endpoint) and 4-months post-baseline (secondary endpoint). Engagement, conceptualised as uptake, adherence and completion, will also be assessed 6-weeks post-baseline. Mixed-effects linear modelling will be used to conduct intention-to-treat analyses to determine whether reductions in depressive symptoms and secondary outcomes are greater for conditions receiving ClearlyMe® relative to control at 6-weeks and 4-months post-baseline and greater for intervention adherers relative to non-adherers. To minimise risk, participants will be encouraged to use the Get Help section of the app and can also opt to receive a call from the team clinical psychologist at baseline, and at the 6-week and 4-month post-baseline assessments when reporting suicidal ideation. DISCUSSION: This is the first clinical trial examining a CBT smartphone app specifically designed for adolescent depression. It will provide empirical evidence on the effects of ClearlyMe® on depressive symptoms when used with and without guided support. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ACTRN12622000131752). UNIVERSAL TRIAL NUMBER: U1111-1271-8519.

The effectiveness of an Australian community suicide prevention networks program in preventing suicide: a controlled longitudinal study.

BACKGROUND: Suicide is a major issue affecting communities around the world. Community-based suicide prevention approaches can tailor activities at a local level and are recognised as a key component of national suicide prevention strategies. Despite this, research exploring their effects on completed suicides is rare. This study examined the effect of a national program of community suicide prevention networks on suicide rates in catchment areas across Australia. METHODS: Australian suicide data from the National Coronial Information System for 2001-2017 were mapped to geographic catchment areas of community suicide prevention networks and matched control areas with similar characteristics. The effect of network establishment on suicide rates was evaluated using longitudinal models including fixed effects for site type (network or control), time, season, and intervention (network establishment), with site included as a random intercept. RESULTS: Sixty suicide prevention networks were included, servicing areas with a population of 3.5 million. Networks varied in when they were established, ranging from 2007 to 2016. Across the time-period, suicide rates per 100,000 per quarter averaged 3.73 (SD = 5.35). A significant reduction in the suicide rate of 7.0% was found after establishment of networks (IRR = 0.93, 95% CI 0.87 to 0.99, p = .025). CONCLUSION: This study found evidence of an average reduction in suicide rates following the establishment of suicide prevention networks in Australian communities. These findings support the effectiveness of empowering local communities to take action to prevent suicide.

Expression patterns for Bcl-2, EMA, ß-catenin, E-cadherin, PAX8, and MIB1 in thymomas.

The expression of immunohistochemical markers has been extensively investigated in thymomas to assist in the differential diagnosis. We have studied six select markers to determine their utility in the evaluation of these tumors. A series of 126 thymomas including 33 type A, 27 type AB, 20 type B1, 22 type B2, and 24 type B3, were examined utilizing a tissue microarray (TMA) technique with antibodies to e-cadherin, ß-catenin, PAX8, bcl-2, EMA, and MIB-1. Keratin AE1/AE3 and p63 were used for quality control. A significant finding was strong and consistent positivity for bcl-2 in type A (90%) and type AB (88.8%) thymoma, while 100% of B1, B2, and B3 were negative. The distribution of e-cadherin and ß-catenin was not useful for differential diagnosis. E-cadherin and ß-catenin were expressed in a high proportion of all the tumors (92-100%), except for B2 thymoma which showed only 45% expression. A significant increase in the expression of the MIB-1 proliferation marker (mean: 12.8% nuclear positivity) was also observed in B3 thymoma compared with the other histologic types. Statistical significance was confirmed using Kruskal's non-parameterized test for distribution. EMA was generally negative except for spindle cells in the fibrous septa in types A and AB thymoma. PAX8 showed less consistent nuclear staining than p63 and was only widely expressed in 55.7% of cases. Bcl-2 may serve as a useful marker to separate spindle cell thymomas (Type A and AB) from the other types, and the MIB1 proliferation index may be of use to differentiate type B2 from type B3 thymoma.

Observation of Hydrodynamic Flows in Imploding Fusion Plasmas on the National Ignition Facility.

Inertial confinement fusion implosions designed to have minimal fluid motion at peak compression often show significant linear flows in the laboratory, attributable per simulations to percent-level imbalances in the laser drive illumination symmetry. We present experimental results which intentionally varied the mode 1 drive imbalance by up to 4% to test hydrodynamic predictions of flows and the resultant imploded core asymmetries and performance, as measured by a combination of DT neutron spectroscopy and high-resolution x-ray core imaging. Neutron yields decrease by up to 50%, and anisotropic neutron Doppler broadening increases by 20%, in agreement with simulations. Furthermore, a tracer jet from the capsule fill-tube perturbation that is entrained by the hot-spot flow confirms the average flow speeds deduced from neutron spectroscopy.

Myxoinflammatory fibroblastic sarcoma: an immunohistochemical and molecular genetic study of 73 cases.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare, low-grade soft tissue neoplasm preferentially arising in the extremities of young to middle-aged adults characterized histologically by a variegated appearance and absence of a distinctive immunophenotype. Herein we have evaluated a series of 73 cases of MIFS to define potential features and markers that may facilitate diagnosis. An immunohistochemical study with a large panel of antibodies showed strong positivity of the tumor cells for bcl-1 (94.5%), FXIIIa (89%), CD10 (80%), and D2-40 (56%). FISH and array comparative genomic hybridization (aCGH) were performed in a large subset of cases to investigate the utility for detecting the TGFBR3 and OGA t(1;10) rearrangement and BRAF abnormalities. Using a combination of FISH and/or aCGH, t(1;10) was detected in only 3 of 54 cases (5.5%). The aCGH study also demonstrated amplification of VGLL3 on chromosome 3 that was detected in 8 of 20 cases (40%). BRAF alterations were observed by FISH in 4 of 70 cases (5.7%) and correlated with gain of chromosome 3p12 (VGLL3). A novel fusion transcript involving exon 6 of ZNF335 and exon 10 of BRAF was identified in one case. Demonstration of amplification of VGLL3 on chromosome 3 in combination with expression of bcl-1 and FXIIIa may help support the diagnosis, however, due to their low specificity these markers are not sufficient for a definitive diagnosis in the absence of the appropriate clinical-pathological context. Until a more robust genetic or immunohistochemical signature is identified, the diagnosis of MIFS rests on its characteristic clinicopathological features.

Time-Resolved Fuel Density Profiles of the Stagnation Phase of Indirect-Drive Inertial Confinement Implosions.

The implosion efficiency in inertial confinement fusion depends on the degree of stagnated fuel compression, density uniformity, sphericity, and minimum residual kinetic energy achieved. Compton scattering-mediated 50-200 keV x-ray radiographs of indirect-drive cryogenic implosions at the National Ignition Facility capture the dynamic evolution of the fuel as it goes through peak compression, revealing low-mode 3D nonuniformities and thicker fuel with lower peak density than simulated. By differencing two radiographs taken at different times during the same implosion, we also measure the residual kinetic energy not transferred to the hot spot and quantify its impact on the implosion performance.

Neutron Time-of-Flight Measurements of Charged-Particle Energy Loss in Inertial Confinement Fusion Plasmas.

Neutron spectra from secondary ^{3}H(d,n)α reactions produced by an implosion of a deuterium-gas capsule at the National Ignition Facility have been measured with order-of-magnitude improvements in statistics and resolution over past experiments. These new data and their sensitivity to the energy loss of fast tritons emitted from thermal ^{2}H(d,p)^{3}H reactions enable the first statistically significant investigation of charged-particle stopping via the emitted neutron spectrum. Radiation-hydrodynamic simulations, constrained to match a number of observables from the implosion, were used to predict the neutron spectra while employing two different energy loss models. This analysis represents the first test of stopping models under inertial confinement fusion conditions, covering plasma temperatures of k_{B}T≈1-4 keV and particle densities of n≈(12-2)×10^{24} cm^{-3}. Under these conditions, we find significant deviations of our data from a theory employing classical collisions whereas the theory including quantum diffraction agrees with our data.

A Phase II Clinical Trial of Molecular Profiled Neoadjuvant Therapy for Localized Pancreatic Ductal Adenocarcinoma.

OBJECTIVES: One facet of precision medicine is the use of tumor molecular profiling to guide chemotherapeutic selection. We conducted the first prospective clinical trial of molecular profiling to guide neoadjuvant therapy in patients with operable pancreatic ductal adenocarcinoma (PDAC). We hypothesized that more effective systemic therapy would prevent disease progression during neoadjuvant therapy and, therefore, allow more patients to undergo surgery. METHODS: In patients with resectable and borderline resectable (BLR) PDAC, molecular profiling consisted of immunocytochemical staining of pretreatment endoscopic ultrasound-guided fine needle aspiration tumor biopsies using 6 biomarkers. Neoadjuvant systemic therapy was selected based on the molecular profiling results. The primary endpoint was the completion of all intended neoadjuvant therapy and surgery. RESULTS: The trial enrolled 130 patients; 61 (47%) resectable and 69 (53%) BLR. Molecular profiling was reported within a median of 5 business days (IQR: 3). Of the 130 patient samples, 95 (73%) had adequate cellularity for molecular profiling and 92 (71%) patients received molecular profile-directed therapy. Of the 92 patients who had predictive profiling, 74 (80%) received fluoropyrimidine-based therapy and 18 (20%) received gemcitabine-based therapies. Of the 130 patients, 107 (82%) completed all intended neoadjuvant therapy and surgery; 56 (92%) of the 61 with resectable PDAC and 51 (74%) of 69 with BLR PDAC. CONCLUSIONS: We report the first prospective clinical trial that utilized molecular profiling to select neoadjuvant therapy in patients with operable PDAC. Such high resectability rates have not been observed in prior neoadjuvant trials, suggesting that molecular profiling may improve the efficacy of chemotherapy in these patients.

Liquid Structure of Shock-Compressed Hydrocarbons at Megabar Pressures.

We present results for the ionic structure in hydrocarbons (polystyrene, polyethylene) that were shock compressed to pressures of up to 190 GPa, inducing rapid melting of the samples. The structure of the resulting liquid is then probed using in situ diffraction by an x-ray free electron laser beam, demonstrating the capability to obtain reliable diffraction data in a single shot, even for low-Z samples without long range order. The data agree well with ab initio simulations, validating the ability of such approaches to model mixed samples in states where complex interparticle bonds remain, and showing that simpler models are not necessarily valid. While the results clearly exclude the possibility of complete carbon-hydrogen demixing at the conditions probed, they also, in contrast to previous predictions, indicate that diffraction is not always a sufficient diagnostic for this phenomenon.

Fusion Energy Output Greater than the Kinetic Energy of an Imploding Shell at the National Ignition Facility.

A series of cryogenic, layered deuterium-tritium (DT) implosions have produced, for the first time, fusion energy output twice the peak kinetic energy of the imploding shell. These experiments at the National Ignition Facility utilized high density carbon ablators with a three-shock laser pulse (1.5 MJ in 7.5 ns) to irradiate low gas-filled (0.3 mg/cc of helium) bare depleted uranium hohlraums, resulting in a peak hohlraum radiative temperature ∼290 eV. The imploding shell, composed of the nonablated high density carbon and the DT cryogenic layer, is, thus, driven to velocity on the order of 380 km/s resulting in a peak kinetic energy of ∼21 kJ, which once stagnated produced a total DT neutron yield of 1.9×10^{16} (shot N170827) corresponding to an output fusion energy of 54 kJ. Time dependent low mode asymmetries that limited further progress of implosions have now been controlled, leading to an increased compression of the hot spot. It resulted in hot spot areal density (ρr∼0.3 g/cm^{2}) and stagnation pressure (∼360 Gbar) never before achieved in a laboratory experiment.

Diffusion-weighted MRI in paediatric neuroimaging.

Diffusion-weighted imaging (DWI) is a well-established technique in neuroimaging, but the diagnostic value of DWI outside the setting of acute infarct and abscess is sometimes under-recognised particularly in paediatric neuroimaging. DWI also plays an important role in the evaluation of intracranial infection, brain tumours, demyelinating diseases, and metabolic disorders. DWI can assist in the early detection and characterisation of intraocular and skull-base pathology. The cases presented in this article demonstrate the utility of DWI in paediatric neuroimaging. DWI can improve diagnostic sensitivity and in conjunction with other magnetic resonance imaging (MRI) sequences can aid in early diagnosis and management. Obtaining an early diagnosis may avoid potential complications and improve patient outcome.

A smartphone application for treating depressive symptoms: study protocol for a randomised controlled trial.

BACKGROUND: Depression is a commonly occurring disorder linked to diminished role functioning and quality of life. The development of treatments that overcome barriers to accessing treatment remains an important area of clinical research as most people delay or do not receive treatment at an appropriate time. The workplace is an ideal setting to roll-out an intervention, particularly given the substantial psychological benefits associated with remaining in the workforce. Mobile health (mhealth) interventions utilising smartphone applications (apps) offer novel solutions to disseminating evidence based programs, however few apps have undergone rigorous testing. The present study aims to evaluate the effectiveness of a smartphone app designed to treat depressive symptoms in workers. METHODS: The present study is a multicentre randomised controlled trial (RCT), comparing the effectiveness of the intervention to that of an attention control. The primary outcome measured will be reduced depressive symptoms at 3 months. Secondary outcomes such as wellbeing and work performance will also be measured. Employees from a range of industries will be recruited via a mixture of targeted social media advertising and Industry partners. Participants will be included if they present with likely current depression at baseline. Following baseline assessment (administered within the app), participants will be randomised to receive one of two versions of the Headgear application: 1) Intervention (a 30-day mental health intervention focusing on behavioural activation and mindfulness), or 2) attention control app (mood monitoring for 30 days). Participants will be blinded to their allocation. Analyses will be conducted within an intention to treat framework using mixed modelling. DISCUSSION: The results of this trial will provide valuable information about the effectiveness of mhealth interventions in the treatment of depressive symptoms in a workplace context. TRIAL REGISTRATION: The current trial is registered with the Australian and New Zealand Clinical Trials Registry ( ACTRN12617000547347 , Registration date: 19/04/2017).

Cancer cell chemokines direct chemotaxis of activated stellate cells in pancreatic ductal adenocarcinoma.

The mechanisms by which the extreme desmoplasia observed in pancreatic tumors develops remain unknown and its role in pancreatic cancer progression is unsettled. Chemokines have a key role in the recruitment of a wide variety of cell types in health and disease. Transcript and protein profile analyses of human and murine cell lines and human tissue specimens revealed a consistent elevation in the receptors CCR10 and CXCR6, as well as their respective ligands CCL28 and CXCL16. Elevated ligand expression was restricted to tumor cells, whereas receptors were in both epithelial and stromal cells. Consistent with its regulation by inflammatory cytokines, CCL28 and CCR10, but not CXCL16 or CXCR6, were upregulated in human pancreatitis tissues. Cytokine stimulation of pancreatic cancer cells increased CCL28 secretion in epithelial tumor cells but not an immortalized activated human pancreatic stellate cell line (HPSC). Stellate cells exhibited dose- and receptor-dependent chemotaxis in response to CCL28. This functional response was not linked to changes in activation status as CCL28 had little impact on alpha smooth muscle actin levels or extracellular matrix deposition or alignment. Co-culture assays revealed CCL28-dependent chemotaxis of HPSC toward cancer but not normal pancreatic epithelial cells, consistent with stromal cells being a functional target for the epithelial-derived chemokine. These data together implicate the chemokine CCL28 in the inflammation-mediated recruitment of cancer-associated stellate cells into the pancreatic cancer parenchyma.

Bone density and body composition in newly licenced professional jockeys.

The primary objective is the description of bone mineral density (BMD) and body composition in newly licensed jockeys. One in three male, flat jockeys has a very low bone mineral density. Further research is needed to assess the short-term risk of fractures and long-term health implications of these findings. INTRODUCTION: Describe bone mineral density (BMD) and body composition in entry-level male and female, flat and jump jockeys in Great Britain. METHODS: Data was collected on jockeys applying for a professional jockey license between 2013 and 2015. Areal BMD at the spine, femoral neck (FN), total hip and body composition were assessed by dual-energy X-ray absorptiometry (DXA) scan. We examined differences between BMD and body composition by gender and race type (flat or jump). Volumetric bone mineral apparent density (BMAD) of the spine and FN was also calculated to account for group differences in bone size. RESULTS: Seventy-nine male flat jockeys (age 18.5 ± 1.9, BMI 19.0 ± 1.4), 69 male jump (age 20.7 ± 2.0, BMI 20.6 ± 1.3) and 37 female flat jockeys (age 19.3 ± 2.0, BMI 20.8 ± 1.7) took part in this study. Spine BMD Z-scores ≤-2 for male flat, male jump and female flat jockeys were 29, 13 and 2.7%, respectively. Spine BMD was lower in male than female flat jockeys (p<0.001). All BMD scores were lower in male flat compared to male jump jockeys (p<0.001). Body fat percent (BF %) was lower in male flat jockeys compared to male jump and female flat jockeys (p<0.05). Lean mass index (LMI) was lower in male flat compared to male jump jockeys (p<0.001). CONCLUSIONS: Male flat jockeys had a significantly lower BMD, LMI and BF% compared to jump jockeys and female flat jockeys. Male flat jockeys had lower spine BMD scores than females. Individual bone maturation may influence these findings. Further investigation into the relevance of low BMD and altered body composition on jockey health is required.

Normal neuroanatomical variants that may be misinterpreted as disease entities.

Variations of normal development and benign incidental anomalies are frequently observed on diagnostic neuroimaging. It is important these are recognised for what they are, as misinterpretation may result in unnecessary further investigation, follow-up imaging and anxiety. In this article, we review benign intracranial anomalies commonly referred to our unit for specialist neuroradiology advice or multidisciplinary discussion, concerning cysts of the pineal gland and pituitary fossa, vascular anomalies, and perivascular spaces. This article outlines the embryology and development, the various imaging features as well as the clinical relevance and differential diagnoses of each normal neuroanatomical variant.

Generation and Beaming of Early Hot Electrons onto the Capsule in Laser-Driven Ignition Hohlraums.

In hohlraums for inertial confinement fusion (ICF) implosions on the National Ignition Facility, suprathermal hot electrons, generated by laser plasma instabilities early in the laser pulse ("picket") while blowing down the laser entrance hole (LEH) windows, can preheat the capsule fuel. Hard x-ray imaging of a Bi capsule surrogate and of the hohlraum emissions, in conjunction with the measurement of time-resolved bremsstrahlung spectra, allows us to uncover for the first time the directionality of these hot electrons and infer the capsule preheat. Data and Monte Carlo calculations indicate that for most experiments the hot electrons are emitted nearly isotropically from the LEH. However, we have found cases where a significant fraction of the generated electrons are emitted in a collimated beam directly towards the capsule poles, where their local energy deposition is up to 10× higher than the average preheat value and acceptable levels for ICF implosions. The observed "beaming" is consistent with a recently unveiled multibeam stimulated Raman scattering model [P. Michel et al., Phys. Rev. Lett. 115, 055003 (2015)], where laser beams in a cone drive a common plasma wave on axis. Finally, we demonstrate that we can control the amount of generated hot electrons by changing the laser pulse shape and hohlraum plasma.

Central Asia: Kyrgyzstan and the learning experience in the design of pastoral institutions.

The authors analyse the nature of policy development to understand the reasons for institutional change in pasture management in Kyrgyzstan. They use the concept of intentional institutional change, emphasising its incremental nature and the important relationship between belief systems and institutions. The paper explores the relationship between the perceptions and beliefs of policy-makers, the policy interventions they undertake, and the consequences for pastoral migration and practices. The study reveals the gap between the intentions behind such policies and their outcomes, the persistence and importance of pastoral migration, and the learning process that policy-makers undergo. This close look at the development and institutionalisation of new dominant societal beliefs highlights the possible direction of the future development of formal pastoral institutions in Central Asia. Policy-makers should respond better to changes in pastoral mobility and the unsustainable increase in intensified use of natural pastures. Policy-makers must also respond to the growth in conflict over pasture use by becoming more aware of the need for inter-sectoral cooperation. The authors argue that a crucial test for the new formal institutions still lies ahead. The key questions are: whether policy-makers and pasture users can eventually come to hold the same beliefs about what is needed in their society, and what new effective institutions will emerge to define the future of pastoralism in Central Asia.

Les auteurs tentent d'élucider les raisons du changement institutionnel de la gestion des pâturages au Kirghizstan en analysant les modifications apportées dans ce domaine au niveau réglementaire. Ils recourent au concept de changement institutionnel volontariste en soulignant son caractère progressif et l'importance des liens entre les systèmes de croyances et les institutions. Cet article explore les liens entre les perceptions et les croyances des décideurs, leurs interventions en matière réglementaire et les conséquences de ces décisions sur les migrations et les pratiques des pasteurs. L'étude met en lumière le fossé qui sépare les intentions qui animent ces décisions et les résultats concrets obtenus, la persistance et l'ampleur des migrations pastorales et les enseignements que les décideurs en tirent actuellement. Cet examen approfondi de l'élaboration et de l'institutionnalisation de nouvelles croyances sociétales dominantes met en avant des perspectives d'orientations pour le développement futur d'institutions pastorales formelles en Asie centrale. Les décideurs politiques doivent prendre acte du déclin du nomadisme pastoral et de la généralisation d'utilisations intensives et non durables des prairies naturelles, et concevoir des réponses adaptées. Ils doivent également répondre à l'intensification des situations conflictuelles en prenant davantage conscience de la nécessité d'une coopération intersectorielle. Les auteurs estiment que les nouvelles institutions formelles n'ont pas encore pleinement démontré leur efficacité. Il conviendra de répondre à deux questions cruciales, à savoir : les décideurs politiques et les utilisateurs des prairies parviendront-ils à partager une vision commune des besoins de leur société ? Quelles institutions nouvelles et efficaces verront-elles le jour pour définir l'avenir du pastoralisme en Asie centrale ?

Los autores analizan la naturaleza de la planificación de políticas con el fin de entender las razones del cambio institucional en la gestión de los pastizales de Kirguistán. Para ello emplean el concepto de cambio institucional intencionado, haciendo hincapié en su carácter progresivo y en el importante vínculo que existe entre sistemas de creencias e instituciones. Asimismo, examinan la relación entre las percepciones y convicciones de los planificadores, las intervenciones normativas que impulsan y las consecuencias que ello tiene en la migración y los usos de los grupos de pastores. El estudio evidencia el desfase existente entre las intenciones que animan estas políticas y sus resultados, la persistencia e importancia de la migración pastoral y el proceso de aprendizaje por el que pasan los planificadores de políticas. Este detenido análisis de la aparición e institucionalización de nuevas creencias que arraigan en la sociedad señala la posible dirección que puede seguir en el futuro la creación de instituciones pastorales formales en Asia Central. Los planificadores deben tener más en cuenta la menor movilidad de los pastores y el insostenible incremento del uso intensivo de los pastos naturales y encontrar respuesta a esos fenómenos. También deben responder a un nivel creciente de conflicto, para lo cual deben entender la necesidad de procesos de cooperación intersectorial. Los autores postulan que las nuevas instituciones formales aún deben superar pruebas cruciales. Las cuestiones básicas que se plantean son, por un lado, si a la larga los planificadores de políticas y los usuarios de pastizales pueden llegar a compartir una misma visión de lo que necesita su sociedad y, por el otro, qué tipo de instituciones nuevas y eficaces verán la luz para definir el futuro del pastoreo en Asia Central.