BIOMECHANICS OF LATE TWIST INITIATION IN GYMNASTICS

The ccmplexity of the present-day gymnastics artform is a result of the rapid evolution of stunt difficulty in the past decade. The incessant challenge to the limits of difficulty and risk have made once seemingly impossible stunts-particularly, those involving simultaneous twists and rotations-now routine. Twisting, a seemingly innate ability in midair, is in fact in an overwhelming majority of gymnastic maneuvers, initiated from a supporting surface and not in free space. However, it is those fewer instances of late twist initiation by catlike movements that are so aesthetically appealing, and from a biomechanical standpoint, pose interesting questions. Can man twist like a cat? How is twist effected in a torque free environment? Examination of gymnasts in action reveal the late twist to be unsubstantiated solely by the cat twist theory, but rather, by a combination of twist techniques

JOINT MOBILITY AND FORCE APPLICATION DURING THE THRUST PHASE OF THE FRONT HANDSPRING ON FLOOR EXERCISE

The purpose of this study was to conduct a kinetic analysis of the front handspring element as performed on floor exercise by young female gymnasts. Force data as well as flexibility measures with respect to the hip, shoulder and trunk were examined for association with front handspring success. In addition, the predictability of force and impulse generation based on flexibility was examined. Twenty-two girls (Mean age = 12.0 yrs and Mean wgt = 40.4 kg) rated as Class-2 and Class-3 gymnasts comprised the subject .group. Data were recorded with a Kistler Instrument force measurement platform. Results revealed peak vertical impact forces (Mean = 709.3 N) on the order of 1.8 times bodyweight and relatively low vertical impulses (Mean = 94.8 N-sec). Lower yet were horizontal generated forces and impulses. Average hand contact time at take off was 0.30 seconds. Except for the independent variable of shoulder angle, variation in normal and shear impulses could not be explained by variation in joint flexibility. Regression analysis revealed that variations in vertical impulse and horizontal impulse could be explained by variation in shoulder joint flexibility (p < 0.05). Examination of performance ratings with flexibility and dynamometric data revealed only two significant relationships (p < 0.05), those for rating and horizontal impulse and for rating and time of contact. Non-significant relationships were found to exist between performance and degree of shoulder, trunk, and hip flexibility. The results suggest that degree of shoulder--but not trunk nor hip-flexibility can be used to predict impulse of force during the front handspring. However, joint flexibility did not associate strongly with performance level

Mindfulness, socioemotional wealth, and environmental strategy of family businesses.

The study advances knowledge in the field of business strategy and the environment by incorporating mindfulness theory into the research on socioemotional wealth (SEW) and its environmental consequences in family businesses. Using an integrative model, the paper investigates the relationship between mindfulness SEW dimensions and family firms' environmental strategies, specifically in developing sustainable products and processes. This study also proposes the firm's capabilities as a mediator in this relationship, while market turbulence is a moderator in the relationship between the firm's capabilities and sustainable products and processes. The empirical results show that in protecting SEW, specifically in the identification of family members with the firm and binding social ties, mindfulness provides a rich endowment that develops appropriate capabilities to produce sustainable products and processes. While the moderating role of market turbulence is insignificant, we can infer that irrespective of how turbulent (or not) the market is, the firm's capabilities are a key determinant of sustainable products and processes. Our findings offer theoretical and managerial implications for sustainable practices in the family business context

MENGANALISIS SERIKAT PEKERJA (TRADE UNION AND EMPLOYER ASSOCIATION) PADA INDUSTRI MANUFAKTUR

PT. Pos Indonesia (Persero) ialah perusahaan BUMN yang bergerak dibidang jasa pengiriman surat ataupun barang yang mempunyai kantor pusat di Kota Bandung dan mempunyai 11 kantor regional yang terletak di seluruh wilayah Indonesia. Permasalahan banyak yang terjadi pada pekerja yang bekerja di PT. Pos Indonesia (Persero) diantaranya melaksanakan pemutusan hubungan kerja, melakukan pemberhentian sementara, menurunkan jabatan atau melakukan mutasi, tidak mengupah atau mengurangi upah pekerja dan melakukan intimidasi sehingga hal ini membentuk para pekerja untuk membentuk serikat pekerja untuk mendapatkan keadilan mengenai hak yang dimiliki oleh para tenaga kerja. Permasalahan yang paling dasar yang terjadi pada pekerja PT. Pos Indonesia (Persero) cabang Kota Bukittinggi adalah adanya perselisihan kepentingan. Untuk mengupaya pekerja dalam meredakan perselisihan yang terjadi di PT. Pos Indonesia (Persero) Cabang Kota Bukittinggi maka dibentuk serikat pekerja dicabang Kota Bukittinggi yang berpusat di Bandung dan bersifat independen, mandiri, demokratis, dan bertanggung jawab serta tidak berafiliasi pada partai politik maupun organisasi kemasyarakatan

Mechanomodulation of Lipid Membranes by Weakly Aggregating Silver Nanoparticles

Silver nanoparticles (AgNPs) have wide-ranging applications, including as additives in consumer products and in medical diagnostics and therapy. Therefore, understanding how AgNPs interact with biological systems is important for ascertaining any potential health risks due to the likelihood of high levels of human exposure. Besides any severe, acute effects, it is desirable to understand more subtle interactions that could lead to milder, chronic health impacts. Nanoparticles are small enough to be able to enter biological cells and interfere with their internal biochemistry. The initial contact between the nanoparticle and cell is at the plasma membrane. To gain fundamental mechanistic insight into AgNP–membrane interactions, we investigate these phenomena in minimal model systems using a wide range of biophysical approaches applied to lipid vesicles. We find a strong dependence on the medium composition, where colloidally stable AgNPs in a glucose buffer have a negligible effect on the membrane. However, at physiological salt concentrations, the AgNPs start to weakly aggregate and sporadic but significant membrane perturbation events are observed. Under these latter conditions, transient poration and structural remodeling of some vesicle membranes are observed. We observe that the fluidity of giant vesicle membranes universally decreases by an average of 16% across all vesicles. However, we observe a small population of vesicles that display a significant change in their mechanical properties with lower bending rigidity and higher membrane tension. Therefore, we argue that the isolated occurrences of membrane perturbation by AgNPs are due to low-probability mechanomodulation by AgNP aggregation at the membrane