scholarly journals Excessive livestock grazing overrides the positive effects of trees on infiltration capacity and modifies preferential flow in dry Miombo woodlands

Author(s):  
L. Lulandala ◽  
A. Bargués‐Tobella ◽  
C. A. Masao ◽  
G. Nyberg ◽  
U. Ilstedt
2019 ◽  
Vol 45 (2) ◽  
pp. 423
Author(s):  
T. Lasanta

The mountains of Europe, especially in the Mediterranean, have undergone a significant process of revegetation since the mid-20th century with the spread of shrublands and forests in succession stages. This leads to negative effects (degradation of pasture, accumulation of biomass with the subsequent increase in fire risk, loss or trivialized of cultural landscapes, etc.) and other positive ones (greater rewilding of landscapes, recovery of forest life, more CO2 fixation, less soil erosion, etc.). Thus, two alternatives must be put forward: either allow the rewilding process to continue, or intervene in the region to reduce the negative effects of revegetation.In this paper, the literature forms the base for a discussion on the main interventions in the territory: extensive livestock grazing, combined with prescribed fires and shrub clearing. Prescribed fires are found to be insufficient to control the spread of shrublands, and in some cases promotes its regrowth (Echinospartum horridum), as well as degrading the pasture land and increasing soil erosion. On the other hand, clearing shrubland has positive effects: a reduction in wildfires, increased livestock numbers, and improved indicators of heterogeneity and fragmentation of the landscape.


1993 ◽  
Vol 8 (1) ◽  
pp. 19-23 ◽  
Author(s):  
John D. Williams ◽  
John C. Buckhouse

Abstract Trees are often harvested in small woodlots for the dual purpose of generating revenue and expanding or enhancing woodland pasture for livestock and wildlife. Following such an effort, in a two-part study we compared the runoff and erosion potential in harvested and nonharvested sites. The tree harvest was conducted on snow and frozen soil and used prescribed skid trails. In the first part of the study, runoff plots were installed and monitored for 2 winters and 1 summer to determine if runoff and erosion resulting from natural precipitation events occurred from either of two treatments; a harvested site or a comparable nonharvested site. In the second part of the study, simulated rainfall was applied to a separate set of runoff plots to determine endpoint infiltration capacity and to make projections of infiltration and erosion response to anticipated livestock grazing. Rainfall was applied to each plot at three subsequent levels of ground cover manipulation: undisturbed vegetation, clipped vegetation, and vegetation and organic soil horizon removed. No runoff or sediment production was recorded between September 1986 and December 1987 in either harvested or nonharvested treatments in the plots monitoring response to natural rainfall. In addition, runoff and sediment production did not occur as a result of simulated rainfall in either site regardless of the ground cover treatment. The same result was obtained when rainfall was applied for an extended period and at an increased rate of application. The lack of runoff can be attributed to site conditions, especially the well-developed biomass in the upper soil horizons, and the method and season of logging. If the tree harvest procedures are repeated in similar sites, similar results may be expected. West. J. Appl. For. 8(1):19-23.


2020 ◽  
Vol 63 (4) ◽  
pp. 1018-1032
Author(s):  
Chia-Hsin Wu ◽  
Roger W. Chan

Purpose Semi-occluded vocal tract (SOVT) exercises with tubes or straws have been widely used for a variety of voice disorders. Yet, the effects of longer periods of SOVT exercises (lasting for weeks) on the aging voice are not well understood. This study investigated the effects of a 6-week straw phonation in water (SPW) exercise program. Method Thirty-seven elderly subjects with self-perceived voice problems were assigned into two groups: (a) SPW exercises with six weekly sessions and home practice (experimental group) and (b) vocal hygiene education (control group). Before and after intervention (2 weeks after the completion of the exercise program), acoustic analysis, auditory–perceptual evaluation, and self-assessment of vocal impairment were conducted. Results Analysis of covariance revealed significant differences between the two groups in smoothed cepstral peak prominence measures, harmonics-to-noise ratio, the auditory–perceptual parameter of breathiness, and Voice Handicap Index-10 scores postintervention. No significant differences between the two groups were found for other measures. Conclusions Our results supported the positive effects of SOVT exercises for the aging voice, with a 6-week SPW exercise program being a clinical option. Future studies should involve long-term follow-up and additional outcome measures to better understand the efficacy of SOVT exercises, particularly SPW exercises, for the aging voice.


2019 ◽  
Vol 4 (6) ◽  
pp. 1589-1594
Author(s):  
Yvonne van Zaalen ◽  
Isabella Reichel

Purpose Among the best strategies to address inadequate speech monitoring skills and other parameters of communication in people with cluttering (PWC) is the relatively new but very promising auditory–visual feedback (AVF) training ( van Zaalen & Reichel, 2015 ). This study examines the effects of AVF training on articulatory accuracy, pause duration, frequency, and type of disfluencies of PWC, as well as on the emotional and cognitive aspects that may be present in clients with this communication disorder ( Reichel, 2010 ; van Zaalen & Reichel, 2015 ). Methods In this study, 12 male adolescents and adults—6 with phonological and 6 with syntactic cluttering—were provided with weekly AVF training for 12 weeks, with a 3-month follow-up. Data was gathered on baseline (T0), Week 6 (T1), Week 12 (T2), and after follow-up (T3). Spontaneous speech was recorded and analyzed by using digital audio-recording and speech analysis software known as Praat ( Boersma & Weenink, 2017 ). Results The results of this study indicated that PWC demonstrated significant improvements in articulatory rate measurements and in pause duration following the AVF training. In addition, the PWC in the study reported positive effects on their ability to retell a story and to speak in more complete sentences. PWC felt better about formulating their ideas and were more satisfied with their interactions with people around them. Conclusions The AVF training was found to be an effective approach for improving monitoring skills of PWC with both quantitative and qualitative benefits in the behavioral, cognitive, emotional, and social domains of communication.


2001 ◽  
Vol 120 (5) ◽  
pp. A314-A315
Author(s):  
D FRANCHIMONT ◽  
J GALON ◽  
M VACCHIO ◽  
R VISCONTI ◽  
G CHROUSOS ◽  
...  

GeroPsych ◽  
2011 ◽  
Vol 24 (2) ◽  
pp. 83-92 ◽  
Author(s):  
Valentina A. Tesky ◽  
Christian Thiel ◽  
Winfried Banzer ◽  
Johannes Pantel

To investigate the effects of leisure activities on cognitive performance of healthy older subjects, an innovative intervention program was developed. Frequent participation in cognitively stimulating activities (i.e., reading, playing chess, or playing music) is associated with reduced risk of dementia. AKTIVA (active cognitive stimulation – prevention in the elderly) is an intervention program designed to enhance cognitive stimulation in everyday life by increasing cognitive stimulating leisure activities. The present study determines the effects of AKTIVA on cognitive function, mood and attitude toward aging in a sample of older participants from the general population. Several measurement instruments were used including the Alzheimer’s Disease Assessment Scale (ADAS-Cog), the Trail-Making Test (TMT), and the Memory Complaint Questionnaire (MAC-Q). Initially, the sample consisted of 307 older persons (170 female, 72 ± 7 years). The intervention was evaluated with a randomized, controlled pre-post follow-up design. Participants were randomly assigned to one of three conditions: AKTIVA intervention (n = 126), AKTIVA intervention plus nutrition and exercise counseling (n = 84), no-intervention control group (n = 97). The AKTIVA intervention consisted of 8 weekly sessions and two booster sessions after a break of 4 months. Participation in the group program resulted in positive effects on cognitive function and attitude toward aging for subassembly groups. Older persons (≥ 75 years) showed enhanced speed of information processing (by TMT Version A) (F = 4.17*, p < .05); younger participants (< 75 years) showed an improvement in subjective memory decline (by MAC-Q) (F = 2.55*, p < .05). Additionally, AKTIVA enhanced the frequency of activities for leisure activities for subassembly groups. The results of this study suggest that the AKTIVA program can be used to increase cognitively stimulating leisure activities in the elderly. Further research is necessary to identify the long-term effects of this intervention particularly with respect to the prevention of dementia.


2014 ◽  
Vol 58 (3) ◽  
pp. 111-124 ◽  
Author(s):  
Sonja Sobiraj ◽  
Sabine Korek ◽  
Thomas Rigotti

Men’s professional work roles require different attributes according to the gender-typicality of their occupation (female- versus male-dominated). We predicted that levels of men’s strain and job satisfaction would be predicted by levels of self-ascribed instrumental and expressive attributes. Therefore, we tested for positive effects of instrumentality for men in general, and instrumentality in interaction with expressiveness for men in female-dominated occupations in particular. Data were based on a survey of 213 men working in female-dominated occupations and 99 men working in male-dominated occupations. We found instrumentality to be negatively related to men’s strain and positively related to their job satisfaction. We also found expressiveness of men in female-dominated occupations to be related to reduced strain when instrumentality was low. This suggests it is important for men to be able to identify highly with either instrumentality or expressiveness when regulating role demands in female-dominated occupations.


2018 ◽  
Vol 62 (2) ◽  
pp. 97-107 ◽  
Author(s):  
Nina Keith

Abstract. The positive effects of goal setting on motivation and performance are among the most established findings of industrial–organizational psychology. Accordingly, goal setting is a common management technique. Lately, however, potential negative effects of goal-setting, for example, on unethical behavior, are increasingly being discussed. This research replicates and extends a laboratory experiment conducted in the United States. In one of three goal conditions (do-your-best goals, consistently high goals, increasingly high goals), 101 participants worked on a search task in five rounds. Half of them (transparency yes/no) were informed at the outset about goal development. We did not find the expected effects on unethical behavior but medium-to-large effects on subjective variables: Perceived fairness of goals and goal commitment were least favorable in the increasing-goal condition, particularly in later goal rounds. Results indicate that when designing goal-setting interventions, organizations may consider potential undesirable long-term effects.


2007 ◽  
Vol 21 (2) ◽  
pp. 91-99 ◽  
Author(s):  
Yunfeng Sun ◽  
Yinling Zhang ◽  
Ning He ◽  
Xufeng Liu ◽  
Danmin Miao

Abstract. Caffeine placebo expectation seems to improve vigilance and cognitive performance. This study investigated the effect of caffeine and placebo expectation on vigilance and cognitive performance during 28 h sleep deprivation. Ten healthy males volunteered to take part in the double-blind, cross-over study, which required participants to complete five treatment periods of 28 h separated by 1-week wash-out intervals. The treatments were no substance (Control); caffeine 200 mg at 00:00 (C200); placebo 200 mg at 00:00 (P200); twice caffeine 200 mg at 00:00 and 04:00 (C200-C200); caffeine 200 mg at 00:00 and placebo 200 mg at 04:00 (C200-P200). Participants were told that all capsules were caffeine and given information about the effects of caffeine to increase expectation. Vigilance was assessed by a three-letter cancellation test, cognitive functions by the continuous addition test and Stroop test, and cardiovascular regulation by heart rate and blood pressure. Tests were performed bihourly from 00:00 to 10:00 of the second day. Results indicated that C200-P200 and C200-C200 were more alert (p < .05) than Control and P200. Their cognitive functions were higher (p < .05) than Control and P200. Also, C200-P200 scored higher than C200 in the letter cancellation task (p < .05). No test showed any significant differences between C200-P200 and C200-C200. The results demonstrated that the combination of caffeine 200 mg and placebo 200 mg expectation exerted prolonged positive effects on vigilance and cognitive performance.


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