@article{BaritelloKhajooeiEngeletal.2020,
  author    = {Baritello, Omar and Khajooei, Mina and Engel, Tilman and Kopinski, Stephan and Quarmby, Andrew James and M{\"u}ller, Steffen and Mayer, Frank},
  title     = {Neuromuscular shoulder activity during exercises with different combinations of stable and unstable weight mass},
  series = {BMC sports science, medicine and rehabilitation},
  volume    = {12},
  journal   = {BMC sports science, medicine and rehabilitation},
  number    = {1},
  publisher = {BioMed Central},
  address   = {London},
  issn      = {2052-1847},
  doi       = {10.1186/s13102-020-00168-x},
  pages     = {14},
  year      = {2020},
  abstract  = {Background Recent shoulder injury prevention programs have utilized resistance exercises combined with different forms of instability, with the goal of eliciting functional adaptations and thereby reducing the risk of injury. However, it is still unknown how an unstable weight mass (UWM) affects the muscular activity of the shoulder stabilizers. Aim of the study was to assess neuromuscular activity of dynamic shoulder stabilizers under four conditions of stable and UWM during three shoulder exercises. It was hypothesized that a combined condition of weight with UWM would elicit greater activation due to the increased stabilization demand. Methods Sixteen participants (7 m/9 f) were included in this cross-sectional study and prepared with an EMG-setup for the: Mm. upper/lower trapezius (U.TA/L.TA), lateral deltoid (DE), latissimus dorsi (LD), serratus anterior (SA) and pectoralis major (PE). A maximal voluntary isometric contraction test (MVIC; 5 s.) was performed on an isokinetic dynamometer. Next, internal/external rotation (In/Ex), abduction/adduction (Ab/Ad) and diagonal flexion/extension (F/E) exercises (5 reps.) were performed with four custom-made-pipes representing different exercise conditions. First, the empty-pipe (P; 0.5 kg) and then, randomly ordered, water-filled-pipe (PW; 1 kg), weight-pipe (PG; 4.5 kg) and weight + water-filled-pipe (PWG; 4.5 kg), while EMG was recorded. Raw root-mean-square values (RMS) were normalized to MVIC (\%MVIC). Differences between conditions for RMS\%MVIC, scapular stabilizer (SR: U.TA/L.TA; U.TA/SA) and contraction (CR: concentric/eccentric) ratios were analyzed (paired t-test; p <= 0.05; Bonferroni adjusted alpha = 0.008). Results PWG showed significantly greater muscle activity for all exercises and all muscles except for PE compared to P and PW. Condition PG elicited muscular activity comparable to PWG (p > 0.008) with significantly lower activation of L.TA and SA in the In/Ex rotation. The SR ratio was significantly higher in PWG compared to P and PW. No significant differences were found for the CR ratio in all exercises and for all muscles. Conclusion Higher weight generated greater muscle activation whereas an UWM raised the neuromuscular activity, increasing the stabilization demands. Especially in the In/Ex rotation, an UWM increased the RMS\%MVIC and SR ratio. This might improve training effects in shoulder prevention and rehabilitation programs.},
  language  = {en}
}
@article{AlirezaeizanjaniGrossmannPfeiferetal.2020,
  author    = {Alirezaeizanjani, Zahra and Großmann, Robert and Pfeifer, Veronika and Hintsche, Marius and Beta, Carsten},
  title     = {Chemotaxis strategies of bacteria with multiple run modes},
  series = {Science advances},
  volume    = {6},
  journal   = {Science advances},
  number    = {22},
  publisher = {American Association for the Advancement of Science},
  address   = {Washington},
  issn      = {2375-2548},
  doi       = {10.1126/sciadv.aaz6153},
  pages     = {8},
  year      = {2020},
  abstract  = {Bacterial chemotaxis-a fundamental example of directional navigation in the living world-is key to many biological processes, including the spreading of bacterial infections. Many bacterial species were recently reported to exhibit several distinct swimming modes-the flagella may, for example, push the cell body or wrap around it. How do the different run modes shape the chemotaxis strategy of a multimode swimmer? Here, we investigate chemotactic motion of the soil bacterium Pseudomonas putida as a model organism. By simultaneously tracking the position of the cell body and the configuration of its flagella, we demonstrate that individual run modes show different chemotactic responses in nutrition gradients and, thus, constitute distinct behavioral states. On the basis of an active particle model, we demonstrate that switching between multiple run states that differ in their speed and responsiveness provides the basis for robust and efficient chemotaxis in complex natural habitats.},
  language  = {en}
}
@article{KhajooeiLinMayeretal.2019,
  author    = {Khajooei, Mina and Lin, Chiao-I and Mayer, Frank and Mueller, Steffen},
  title     = {Muscle activity and strength in maximum isokinetic legpress testing with unstable footplates in active individuals},
  series = {Isokinetics and exercise science : official journal of the European Isokinetic Society},
  volume    = {27},
  journal   = {Isokinetics and exercise science : official journal of the European Isokinetic Society},
  number    = {3},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {0959-3020},
  doi       = {10.3233/IES-182206},
  pages     = {177 -- 183},
  year      = {2019},
  abstract  = {BACKGROUND: Compensating unstable situations is an important functional capability to maintain joint stability, to compensate perturbations and to prevent (re-)injury. Therefore, reduced maximum strength and altered neuromuscular activity are expected by inducing instability to load test situations. Possible effects are not clear for induced instability during maximum legpress tests in healthy individuals. OBJECTIVE: To compare isokinetic legpress (LP) strength and lower-leg muscle activity using stable (S) and unstable (UN) footplates. METHODS: 16 males (28 +/- 4 yrs, 179 +/- 7 cm, 75 +/- 8 kg) performed five maximum LP in concentric (CON) and eccentric (ECC) mode. The maximum force (Fmax) and muscle activity were measured under conditions of S and UN footplates. The tested muscles comprised of the tibialis anterior (TA), peroneus longus (PL) and soleus (SOL) and their activity were quantified against the MVIC of each muscle respectively. RESULTS: The main finding revealed a significant reduction in Fmax under UN condition: 11.9 +/- 11.3\% in CON and 23.5 +/- 47.8\% in ECC (P < 0.05). Significant findings were also noted regarding the RMS derived values of the EMG of PL and TA. CONCLUSION: Unstable LP reduced force generation and increased the activity of PL and TA muscles which confirmed greater neuromuscular effort to compensate instability. This may have some implications for resistance testing and training coupled with an unstable base in the prevention and rehabilitation of injury to the neuromusculoskeletal system.},
  language  = {en}
}
@article{FeldmannLevermann2015,
  author    = {Feldmann, Johannes and Levermann, Anders},
  title     = {Collapse of the West Antarctic Ice Sheet after local destabilization of the Amundsen Basin},
  series = {Proceedings of the National Academy of Sciences of the United States of America},
  volume    = {112},
  journal   = {Proceedings of the National Academy of Sciences of the United States of America},
  number    = {46},
  publisher = {National Acad. of Sciences},
  address   = {Washington},
  issn      = {0027-8424},
  doi       = {10.1073/pnas.1512482112},
  pages     = {14191 -- 14196},
  year      = {2015},
  abstract  = {The future evolution of the Antarctic Ice Sheet represents the largest uncertainty in sea-level projections of this and upcoming centuries. Recently, satellite observations and high-resolution simulations have suggested the initiation of an ice-sheet instability in the Amundsen Sea sector of West Antarctica, caused by the last decades' enhanced basal ice-shelf melting. Whether this localized destabilization will yield a full discharge of marine ice from West Antarctica, associated with a global sea-level rise of more than 3 m, or whether the ice loss is limited by ice dynamics and topographic features, is unclear. Here we show that in the Parallel Ice Sheet Model, a local destabilization causes a complete disintegration of the marine ice in West Antarctica. In our simulations, at 5-km horizontal resolution, the region disequilibrates after 60 y of currently observed melt rates. Thereafter, the marine ice-sheet instability fully unfolds and is not halted by topographic features. In fact, the ice loss in Amundsen Sea sector shifts the catchment's ice divide toward the Filchner-Ronne and Ross ice shelves, which initiates grounding-line retreat there. Our simulations suggest that if a destabilization of Amundsen Sea sector has indeed been initiated, Antarctica will irrevocably contribute at least 3 m to global sea-level rise during the coming centuries to millennia.},
  language  = {en}
}