scholarly journals Factors affecting windstorm damage at the stand level in hemiboreal forests in Latvia: case study of 2005 winter storm

Silva Fennica ◽  
2018 ◽  
Vol 52 (4) ◽  
Author(s):  
Janis Donis ◽  
Mara Kitenberga ◽  
Guntars Snepsts ◽  
Edgars Dubrovskis ◽  
Aris Jansons
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Canopy Layer ◽  
Tree Species Composition ◽  
Management Planning ◽  
Factors Affecting ◽  
Forest Management Planning ◽  
Forest Resilience ◽  
Socio Economic Impact ◽  
Mineral Soils

In managed European hemiboreal forests, windstorms have a notable ecological and socio-economic impact. In this study, stand properties affecting windstorm damage occurrence at the stand-level were assessed using a Generalized Linear Mixed model. After 2005 windstorm, 5959 stands dominated by birch ( spp.), Scots pine ( L.) and Norway spruce ( (L.) Karst.), with mean height > 10 m were inventoried. Windstorm damage was positively associated with spruce and pine-dominated stands, increasing mean height, fresh forest edges, decreasing time since the last thinning and stronger wind gusts. Tree species composition – mixed or monodominant – was not statistically significant in the model; while, the admixture of spruce in the canopy layer was positively associated with higher windstorm damage. Stands on peat soils were more damaged than stands on mineral soils. Birch stands were more damaged than pine stands. This information could be used in forest management planning, selection of silvicultural treatments to increase forest resilience to natural disturbances.BetulaPinus sylvestrisPicea abies

scholarly journals Analyzing Child Malnutrition in Bangladesh: Generalized Linear Mixed Model Approach

2016 ◽  
Vol 64 (2) ◽  
pp. 163-167
Author(s):  
Tahmidul Islam ◽  
Md Golam Rabbani ◽  
Wasimul Bari
Keyword(s):  
Mixed Model ◽  
Sampling Design ◽  
Linear Mixed Model ◽  
Generalized Linear Mixed Model ◽  
Child Malnutrition ◽  
Demographic Health Survey ◽  
Factors Affecting ◽  
Mixed Model Approach ◽  
Potential Factors ◽  
Model Approach

Child malnutrition is a serious issue for overall child health and future development. Stunting is a key anthropometric indicator of child malnutrition. Because of the nature of sampling design used in Bangladesh Demographic Health Survey, 2011, responses obtained from children under same family might be correlated. Again, children residing in same cluster may also be correlated. To tackle this problem, generalized linear mixed model (GLMM), instead of usual fixed effect logistic regression model, has been utilized in this paper to find out potential factors affecting child malnutrition. Model performances have also been compared. Dhaka Univ. J. Sci. 64(2): 163-167, 2016 (July)

scholarly journals A Comprehensive County Level Framework to Identify Factors Affecting Hospital Capacity and Predict Future Hospital Demand

2021 ◽  
Author(s):  
Tanmoy Bhowmik ◽  
Naveen Eluru
Keyword(s):  
High Resolution ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Health Planning ◽  
Health Indicators ◽  
County Level ◽  
Remedial Measures ◽  
Factors Affecting ◽  
Per Capita ◽  
Usage Rates

SUMMARYBackgroundAs of February 19, 2021, our review yielded a small number of studies that investigated high resolution hospitalization demand data from a public health planning perspective. The earlier studies compiled were conducted early in the pandemic and do not include any analysis of the hospitalization trends in the last 3 months when the US experienced a substantial surge in hospitalization and ICU demand. The earlier studies also focused on COVID 19 transmission influence on COVID 19 hospitalization rates. While this emphasis is understandable, there is evidence to suggest that non COVID hospitalization demand is being displaced due to the hospitalization and ICU surge. Further, with the discovery of multiple mutated variants of COVID 19, it is important to remain vigilant in an effort to control the pandemic. Given these circumstances, the development of a high resolution framework that examines overall hospitalizations and ICU usage rate for COVID and non COVID patients would allow us to build a prediction system that can identify potential vulnerable locations for hospitalization capacity in the nation so that appropriate remedial measures can be planned.MethodThe current study recognizes that COVID 19 has affected overall hospitalizations – not only COVID 19 hospitalizations. Drawing from the recently released Department of Health and Human services (DHH) weekly hospitalization data (or the time period August 28th, 2020 to January 22nd, 2021.), we study the overall hospitalization and ICU usage as two components: COVID 19 hospitalization and ICU per capita rates; and non COVID hospitalization and ICU per capita rates. A mixed linear mixed model is adopted to study the response variables in our study. The estimated models are subsequently employed to generate predictions for county level hospitalization and ICU usage rates in the future under a host of COVID 19 transmission scenarios considering the new variants of COVID 19 and vaccination impacts.FindingsWe find a significant association of the virus transmissibility with COVID (positive) and non COVID (negative) hospitalization and ICU usage rates. Several county level factors including demographics, mobility and health indicators are also found to be strongly associated with the overall hospitalization and ICU demand. Among the various scenarios considered, the results indicate a small possibility of a new wave of infections that can substantially overload hospitalization and ICU usage. In the scenario where vaccinations proceed as expected reducing transmission, our results indicate that hospitalizations and ICU usage rates are likely to reduce significantly.InterpretationThe research exercise presents a framework to predict evolving hospitalization and ICU usage trends in response to COVID 19 transmission rates while controlling for other factors. Our work highlights how future hospitalization demand varies by location and time in response to a range of pessimistic and optimistic scenarios. Further, the exercise allows us to identify vulnerable counties and regions under stress with high hospitalization and ICU rates that can be assisted with remedial measures. The model will also allow hospitals to understand evolving displaced non COVID hospital demand.

Empirical performance of estimation methods in Beta mixed models with application to ecological data

2020 ◽  
Vol 15 (2) ◽  
pp. 2279-2293
Author(s):  
Saliou Diouf ◽  
Bruno Enagnon Lokonon ◽  
Freedath Djibril Moussa ◽  
GLèLè KAKAï
Keyword(s):  
Mixed Models ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Real Life ◽  
Estimation Methods ◽  
Simulation Design ◽  
Ecological Data ◽  
Factors Affecting ◽  
Real Life Data ◽  
Empirical Performance

This study uses a Monte Carlo simulation design to assess the performance of Beta and linear mixed models on bounded response variables through comparison of four estimation methods. Four factors affecting the performance of the estimation methods were considered: the number of groups, the number of observations per group, the variance and distribution of the random effects. Our results showed that, for small number of groups (less than 30), the Beta mixed model outperformed the linear mixed model whatever the size of the groups. In the case of a large number of groups (superior or equal to 30), both approaches showed relatively close performance. The results from the simulation study have been illustrated with real life data.

scholarly journals Foraging Behaviour of the Black-Headed Heron at Kibimba Rice Scheme, Eastern Uganda

2020 ◽  
pp. 83-90
Author(s):  
Sarah Nachuha ◽  
Polycarp M. Mwima
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Nearest Neighbor ◽  
Prey Availability ◽  
Phase 1 ◽  
Interference Competition ◽  
Prey Abundance ◽  
Growth Stages ◽  
Factors Affecting ◽  
Feeding Success

Variations in the factors affecting prey availability directly impact on the spatial dispersion of foraging birds. The feeding success and efficiency of the Black-headed Heron (Ardea melanocephala) was examined in the different growth stages/phases of paddy rice, namely: Ploughed fields, Phase 1 fields (2 weeks-1 month after sowing) and Harvested fields. Feeding success of the Black-headed Heron varied significantly across the rice growth stage. This variation was explained by a combination of factors such water depth, waterbird abundance, Nearest Neighbor Distance (NND) and food or prey abundance (except amphibian abundance). Statistical analysis were conducted using Genstat Version 8.1 (VSN Intl.2003, in which a General Linear Mixed Model were used to examine the variation in each behavioural measure. Foraging in aggregations on rice paddies seems to be more beneficial to the Black-headed Heron. The closeness to a conspecific had a positive effect on the feeding efficiency of the Black-headed Heron as they foraged on fields with abundant prey (Phase 1) and a negative effect on fields with less abundant prey (Ploughed fields). Generally, the data seem to suggest that there is a functional relationship between the Black-headed Heron, and prey abundance, and the absence of interference competition on rice fields.

scholarly journals Remodelling of femoral head deformity after hip reconstructive surgery in patients with cerebral palsy

2021 ◽  
Vol 103-B (1) ◽  
pp. 198-203
Author(s):  
Jae Jung Min ◽  
Soon-Sun Kwon ◽  
Ki Hyuk Sung ◽  
Kyoung Min Lee ◽  
Chin Youb Chung ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Femoral Head ◽  
Reconstructive Surgery ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Pelvic Osteotomy ◽  
System Level ◽  
Factors Affecting ◽  
Neck Shaft Angle ◽  
Hip Displacement

Aims Hip displacement, common in patients with cerebral palsy (CP), causes pain and hinders adequate care. Hip reconstructive surgery (HRS) is performed to treat hip displacement; however, only a few studies have quantitatively assessed femoral head sphericity after HRS. The aim of this study was to quantitatively assess improvement in hip sphericity after HRS in patients with CP. Methods We retrospectively analyzed hip radiographs of patients who had undergone HRS because of CP-associated hip displacement. The pre- and postoperative migration percentage (MP), femoral neck-shaft angle (NSA), and sphericity, as determined by the Mose hip ratio (MHR), age at surgery, Gross Motor Function Classification System level, surgical history including Dega pelvic osteotomy, and triradiate cartilage status were studied. Regression analyses using linear mixed model were performed to identify factors affecting hip sphericity improvement. Results A total of 108 patients were enrolled. The mean preoperative MP was 58.3% (SD 31.7%), which improved to 9.1% (SD 15.6%) at the last follow-up. NSA and MHR improved from 156.5° (SD 11.5°) and 82.3% (SD 8.6%) to 126.0° (SD 18.5°) and 89.1% (SD 9.0%), respectively. Factors affecting the postoperative MHR were preoperative MP (p = 0.005), immediate postoperative MP (p = 0.032), and history of Dega osteotomy (p = 0.046). Conclusion We found that hip sphericity improves with HRS. Preoperative MP, reduction quality, and acetabular coverage influence femoral head remodelling. We recommend that surgeons should consider intervention early before hip displacement progresses and that during HRS, definite reduction and coverage of the femoral head should be obtained. Cite this article: Bone Joint J 2021;103-B(1):198–203.

scholarly journals Validating tree species composition in forest resource inventory for Nipissing Forest, Ontario, Canada

2007 ◽  
Vol 83 (2) ◽  
pp. 247-251 ◽  
Author(s):  
Fred Pinto ◽  
Dan Rouillard ◽  
Jean-Marie Sobze ◽  
Michael Ter-Mikaelian
Keyword(s):  
Forest Management ◽  
Species Composition ◽  
Field Data ◽  
Forest Resource ◽  
Tree Species Composition ◽  
Management Planning ◽  
Forest Management Planning ◽  
Resource Inventory ◽  
Forest Resource Inventory ◽  
Level Of Agreement

Species composition estimated from forest resource inventory (FRI) was validated using field data collected in 136 stands in Nipissing Forest (Ontario, Canada). FRI- and field-based species composition matched in 54% and 56% of cases using stand count and area coverage, respectively. Possible causes of discrepancy between FRI- and field-based species composition are discussed. Low level of agreement between FRI and field data indicated a need for more extensive studies on FRI validation prior to its use for forest management planning. Key words: forest resource inventory, FRI, forest unit, photo-interpretation, timber cruise

scholarly journals Abiotic and biotic factors affecting the denning behaviors in Asiatic black bears Ursus thibetanus

2015 ◽  
Vol 97 (1) ◽  
pp. 128-134 ◽  
Author(s):  
Toshiaki Yamamoto ◽  
Hiroo Tamatani ◽  
Junpei Tanaka ◽  
Gen Oshima ◽  
Serina Mura ◽  
...  
Keyword(s):  
Mixed Model ◽  
Linear Mixed Model ◽  
Abiotic Factors ◽  
Black Bears ◽  
Biotic Factors ◽  
Factors Affecting ◽  
Average Temperature ◽  
Males And Females ◽  
Abiotic And Biotic Factors ◽  
Mast Production

Abstract For bears, numerous associations between biotic and abiotic factors have been reported to correlate with the timing of den entry and emergence; however, an analysis showing which factors influence the timing of den entry and emergence has not been performed enough. In this study, a generalized linear mixed model was generated using 66 entry dates for 26 females and 40 entry dates for 26 males, and 56 emergence dates for 26 females and 25 emergence dates for 18 males between 1999 and 2012. Regarding factors for den entry, the average temperature in November and mast production of Mongolian oaks were significant for both males and females. For the date of den emergence, the average temperature in March affected strongly. For males, good mast production of Mongolian oaks in the previous year was found to be associated with early den emergence. For females, the presence of newborns had a significant influence on their den entry and emergence. This study indicated that denning behavior appears to be regulated by several abiotic and biotic factors and regulation factors are sex specific.

scholarly journals Evaluation of factors affecting external tibial torsion in patients with cerebral palsy

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jae Jung Min ◽  
Soon-Sun Kwon ◽  
Kyu Tae Kim ◽  
Young Choi ◽  
Ki Hyuk Sung ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Imaging Study ◽  
Femoral Anteversion ◽  
Affecting Factors ◽  
Tibial Torsion ◽  
Factors Affecting ◽  
3 Dimensional ◽  
Gmfcs Level

Abstract Background Gait deviation and associated torsional problems are common in patients with cerebral palsy (CP). Although femoral anteversion in CP has been extensively reviewed in previous studies, only a few studies have focused on tibial torsion. Therefore, this study aimed to evaluate tibial torsion in patients with CP and investigate the affecting factors. Methods Consecutive patients with cerebral palsy who underwent 3-dimensional computed tomography for the assessment of rotational profiles were reviewed. Femoral anteversion and tibial torsion were measured, and the demographic characteristics of the patients were recorded. A linear mixed model was implemented to overcome the retrospective nature of the study. Results After the implementation of inclusion and exclusion criteria, 472 patients were enrolled for this study. With age, external tibial torsion increased, while femoral anteversion decreased. The factors affecting external tibial torsion were increased femoral anteversion (p = 0.0057), increased age (p < 0.0001), higher Gross Motor Function Classification System (GMFCS) level (p < 0.0001), and involved/uninvolved limbs of hemiplegia (p = 0.0471/p = 0.0047). Conclusions Older age, GMFCS level IV/V, hemiplegia, and increased femoral anteversion were the independent risk factors of increased external tibial torsion; therefore, performing an imaging study is recommended for assessing the extent of tibial torsion in patients with such characteristics.

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