Some behavioral researchers occasionally wish to conduct a median split on a continuous variable and use the result in subsequent modeling to facilitate analytic ease and communication clarity. ...Traditionally, this practice of dichotomization has been criticized for the resulting loss of information and reduction in power. More recently, this practice has been criticized for sometimes producing Type I errors for effects regarding other terms in a model, resulting in a recommendation of the unconditional avoidance of median splits. In this paper, we use simulation studies to demonstrate more thoroughly than has been shown in the literature to date when median splits should not be used, and conversely, to provide nuance and balance to the extant literature regarding when median splits may be used with complete analytical integrity. For the scenario we explicate, the use of a median split is as good as a continuous variable. Accordingly, there is no reason to outright reject median splits, and oftentimes the median split may be preferred as more parsimonious.
The median split: Robust, refined, and revived Iacobucci, Dawn; Posavac, Steven S.; Kardes, Frank R. ...
Journal of consumer psychology,
October 2015, Letnik:
25, Številka:
4
Journal Article
Recenzirano
In this rebuttal, we discuss the comments of Rucker, McShane, and Preacher (2015) and McClelland, Lynch, Irwin, Spiller, and Fitzsimons (2015). Both commentaries raise interesting points, and ...although both teams clearly put a lot of work into their papers, the bottom line is this: our research sets the record straight that median splits are perfectly acceptable to use when independent variables are uncorrelated. The commentaries do a good job of furthering the discussion to help readers better develop their own preferences, which was the purpose of our paper. In the final analysis, neither of the commentaries pose any threat to our findings of the statistical robustness and valid use of median splits, and accordingly we can reassure researchers (and reviewers and journal editors) that they can be confident that when independent variables are uncorrelated, it is totally acceptable to conduct median split analyses.
Abstract An unfavourable and unanticipated pattern of the mandibular sagittal split osteotomy is generally referred to as a ‘bad split’. Few restorative techniques to manage the situation have been ...described. In this article, a classification of reported bad split pattern types is proposed and appropriate salvage procedures to manage the different types of undesired fracture are presented. A systematic review was undertaken, yielding a total of 33 studies published between 1971 and 2015. These reported a total of 458 cases of bad splits among 19,527 sagittal ramus osteotomies in 10,271 patients. The total reported incidence of bad split was 2.3% of sagittal splits. The most frequently encountered were buccal plate fractures of the proximal segment (types 1A–F) and lingual fractures of the distal segment (types 2A and 2B). Coronoid fractures (type 3) and condylar neck fractures (type 4) have seldom been reported. The various types of bad split may require different salvage approaches.
On split common fixed point problems Kraikaew, Rapeepan; Saejung, Satit
Journal of mathematical analysis and applications,
07/2014, Letnik:
415, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Based on the convergence theorem recently proved by the second author, we modify the iterative scheme studied by Moudafi for quasi-nonexpansive operators to obtain strong convergence to a solution of ...the split common fixed point problem. It is noted that Moudafi's original scheme can conclude only weak convergence. As a consequence, we obtain strong convergence theorems for split variational inequality problems for Lipschitz continuous and monotone operators, split common null point problems for maximal monotone operators, and Moudafi's split feasibility problem.
Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease and has emerged among the disorders with the largest increasing incidence in Western countries. Although the diagnosis is ...based on clinical grounds, electromyography (EMG), and nerve conduction studies (NCS) play a crucial role to exclude other potential etiologies of lower motor neuron (LMN) dysfunction. Based on clinical grounds, a peculiar pattern of dissociated atrophy of the intrinsic hand and foot muscles, termed the "split-hand" (SH) and "split-leg" (SL) signs, has been described in a significant proportion of subjects with ALS, even at the early stages of the disease, when symptoms are focal. These signs are rare in neurological and non-neurological diseases other than ALS. In this review, we discussed current evidences concerning SH and SL signs, their pathogenetic hypotheses and neurophysiological findings. We also analyze whether SH and SL signs can be reliable markers in the differential diagnosis and in the prognosis of ALS.
Objectives
This study aimed to analyse the changes in soft tissue and hard tissue stability associated with the split pattern, i.e. long split (LS) or short split (SS), after sagittal split ...osteotomy.
Materials and methods
Patients who underwent sagittal split ramus osteotomy were classified into LS or SS groups according to postoperative computed tomography images. They were examined via lateral cephalography and three-dimensional (3D) optical scanning before surgery (T0) and 1 (T1), 3 (T2), and 12 (T3) months after surgery. Six standard angles (SNA, SNB, ANB, FMA, FMIA, and IMPA) were used as measures of hard tissue change. The two sets of 3D data were superimposed, and the volumetric differences were calculated as the soft tissue change. The areas evaluated were delimited by 10 × 20-mm rectangles in the frontal aspect and a 25 × 25-mm square in the lateral aspect.
Results
A total of 42 sides (26 patients) were analysed, including 20 (16 patients) in the SS group and 22 (16 patients) in the LS group. We found no significant differences in cephalographic angle or soft tissue changes in the frontal aspect between the SS and LS groups. We found significant differences in the subauricular region from T0–T1 (
p
= 0.02), T0–T2 (
p
= 0.03), and T0–T3 (
p
= 0.037) in terms of soft tissue changes in the lateral aspect. The volume increase associated with posterior mandibular movement was greater in the LS group.
Conclusions
We found that LS patients with mandibular prognathism exhibited increased subauricular volumes following mandibular setback.
Clinical relevance
It is essential to predict the postoperative facial profile before surgery. The split pattern after sagittal split osteotomy affects the postoperative profile of patients with mandibular prognathism.
Several studies have reported disproportionate wasting of the flexor muscles of the lower limbs (LL) compared to the extensors in patients with amyotrophic lateral sclerosis (ALS). However, these ...studies have involved small sample sizes (n 〈100), and their findings have been inconsistent. Thus, it remains uncertain whether a distinct pattern of LL muscle weakness is specific to ALS.
To investigate the muscle weakness pattern in the LL at the knee, ankle, and toes in a large cohort of ALS patients and evaluate the relationship between the pattern of muscle strength and the extent of upper (UMN) and lower (LMN) motoneuron impairment.
The strength of flexor and extensor muscle was evaluated in 1250 legs of newly diagnosed ALS patients at the knee, ankle, and foot toes. UMN and LMN burden were assessed using validated scores. Within-subjects ANOVA considering the type of muscle (flexor/extensor) and anatomical sites (knee/ankle/toes) and mixed-factorial ANOVA were conducted to explore the impact of UMN and LMN impairments on the muscle weakness pattern.
Muscle strength showed a significant decline from proximal to distal regions. Indeed both flexor and extensor muscles at the knee outperformed those at the ankle and toes. Within each site, extensor muscles exhibited less strength than flexor, except at the knee. Patients with heightened UMN impairment showed a more marked difference between flexors and extensors within each site, with extensor muscles being more compromised at the ankle and toes. Higher LMN impairment corresponded to a more pronounced weakness in flexor muscles at the ankle and toes compared to those at the knee.
The extensor muscle at the knee and the flexors at the foot and toes displayed relative resistance to ALS disease. UMN impairment amplified the differences between flexor and extensor muscles within each site, while LMN impairment demonstrated a clear distal-to-proximal vulnerability.
•Knee extensors and foot/toe flexors show relative preservation in ALS disease.•UMN damage increases flexor/extensor muscle differences at each site.•LMN damage shows a clear distal-to-proximal muscle weakness pattern.
The use of biochar is expected to improve soil fertility and close nutrient cycles in degraded strongly weathered tropical soils. We, therefore, hypothesized that biochar amendment to tree ...plantations (a) increases nutrient fluxes with litterfall alone and with mineral fertilizer plus lime and (b) reduces N losses reflected by lower δ15N values of litterfall and soils than in unamended controls. We grew the native leguminous Schizolobium parahyba var. amazonicum (Ducke) Barneby and the exotic Gmelina arborea Roxb at two sites. We used a replicated full factorial split–split plot design of amendment of mineral fertilizer plus lime, 3 and 6 t ha−1 biochar, and a control. We collected litterfall biweekly (2012–2013) and topsoil samples (0–0.25 m) in 2009 before tree planting, in 2011 and 2013. Fertilizer plus lime increased the mean annual concentrations of P, Ca and Zn in litterfall but decreased that of Mn. At the same time, fertilizer plus lime increased the annual fluxes of nutrients, Na and Al with litterfall. During the dry season, biochar decreased the N concentration in litterfall and the K flux with litterfall. During the rainy season, biochar increased the concentrations of Ca and Zn in litterfall and their fluxes with litterfall. Biochar did not influence the δ15N values of soil and litterfall after 51 months of tree growth. Fertilizer plus lime decreased the δ15N values of soil, because of the lower δ15N value of the used urea (−0.30‰) than the soil (4.5‰–7.8‰). Moreover, fertilizer plus lime increased the δ15N values of litterfall, possibly because of enhanced 14N leaching from the N‐rich canopies. The amendment of up to 6 t ha−1 biochar did not contribute to close nutrient cycles.
Background
In Japan, a recent gradual increase in deceased donor donation has expanded opportunities for pediatric patients to obtain deceased grafts.
Methods
Forty‐three children underwent deceased ...donor liver transplantation (DDLT) at our institute before February 2020. Twenty‐five patients received a split or reduced graft and 18 patients received a whole graft. The clinical outcomes of DDLT were retrospectively analyzed.
Results
The main organ resource was split/reduced grafts retrieved from adult donors; however, the number of whole grafts retrieved from pediatric donors has increased. The rates of major complications were similar in the two groups. The 5‐year graft survival rate of patients who received a split/reduced graft (78.0%) was lower than that of patients who received a whole graft (88.9%; P = .40). The 3‐year graft survival rates of patients who recently received a split/reduced graft and a whole graft improved to 92.3% and 91.7%, respectively.
Conclusions
The recent amendment of the organ allocation system, especially the introduction of pediatric prioritization, can effectively increase the chance to obtain deceased donor grafts for pediatric DDLT in Japan. The recent refinements in donor and recipient selection and in the surgical technique of split DDLT can improve the outcomes of pediatric DDLT in Japan.
Highlight
Sakamoto and colleagues retrospectively analyzed pediatric deceased donor liver transplantation (DDLT) at Japan’s largest pediatric liver transplant center. Pediatric prioritization has increased the chance to obtain deceased donor grafts, and refinements in donor and recipient selection and in the split DDLT technique can improve the outcomes of pediatric DDLT in Japan.
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