| 1. |
|
|
| 2. |
- Ekeberg, Tomas, 1983-, et al.
(författare)
-
Three-dimensional structure determination with an X-ray laser
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Three-dimensional structure determination of a non-crystalline virus has been achieved from a set of randomly oriented continuous diffraction patterns captured with an X-ray laser. Intense, ultra-short X-ray pulses intercepted a beam of single mimivirus particles, producing single particle X-ray diffraction patterns that are assembled into a three-dimensional amplitude distribution based on statistical consistency. Phases are directly retrieved from the assembled Fourier distribution to synthesize a three-dimensional image. The resulting electron density reveals a pseudo-icosahedral asymmetric virion structure with a compartmentalized interior, within which the DNA genome occupies only about a fifth of the volume enclosed by the capsid. Additional electron microscopy data indicate the genome has a chromatin-like fiber structure that has not previously been observed in a virus.
|
|
| 3. |
- Dahlin, Jakob, 1976-
(författare)
-
Aerosols of Isocyanates, Amines and Anhydrides : Sampling and Analysis
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents methods for air sampling and determination of isocyanates, amines, aminoisocyanates and anhydrides. These organic compounds are generated during thermal degradation of polymers such as polyurethane (PUR) or epoxy.Isocyanates, amines and anhydrides are airway irritants known to cause occupational asthma. Some of the compounds are listed as human carcinogens. Many workers are exposed.Isocyanates and anhydrides are reactive and needs to be immediately derivatized during sampling. Methods have been developed for determination of airborne isocyanates, aminoisocyanates and anhydrides using di-n-butylamine (DBA) as reagent to form stabile urea derivatives or amide derivatives. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) enabled detection limits as low as 10 attomoles. A nitrogen-selective LC-detector enabled quantification of DBA-derivatives in reference solutions. A novel sampler is presented. The sampler consists of a denuder in series with a three-stage cascade impactor and an end filter. The sampler made it possible to reveal the distribution of isocyanates between gas and different particle size fractions. During thermal degradation of PUR, isocyanates were associated to particle size fractions (<1 µm) that may penetrate to the lower airways. The distribution during 8 minutes changes noticeably. Aromatic isocyanates become associated to small particles (<1 µm). As a reference method, air-sampling was performed using an impinger filled with di-n-butylamine (DBA) in toluene, connected in series with a glass fiber filter. There was a good agreement between the denuder-impactor sampler and the reference method.
|
|
| 4. |
- de Rezende, Susanna F., 1989-, et al.
(författare)
-
Lifting with Simple Gadgets and Applications to Circuit and Proof Complexity
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- We significantly strengthen and generalize the theorem lifting Nullstellensatz degree to monotone span program size by Pitassi and Robere (2018) so that it works for any gadget with high enough rank, in particular, for useful gadgets such as equality and greater-than. We apply our generalized theorem to solve two open problems:We present the first result that demonstrates a separation in proof power for cutting planes with unbounded versus polynomially bounded coefficients. Specifically, we exhibit CNF formulas that can be refuted in quadratic length and constant line space in cutting planes with unbounded coefficients, but for which there are no refutations in subexponential length and subpolynomialline space if coefficients are restricted to be of polynomial magnitude.We give the first explicit separation between monotone Boolean formulas and monotone real formulas. Specifically, we give an explicit family of functions that can be computed with monotone real formulas of nearly linear size but require monotone Boolean formulas of exponential size. Previously only a non-explicit separation was known.An important technical ingredient, which may be of independent interest, is that we show that the Nullstellensatz degree of refuting the pebbling formula over a DAG G over any field coincides exactly with the reversible pebbling price of G. In particular, this implies that the standard decision tree complexity and the parity decision tree complexity of the corresponding falsified clause search problem are equal.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Ulenius, Jakob, 1983-
(författare)
-
Maskulinitetens mening : En fenomenologisk undersökning av den psykoterapeutiska situationen
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Masculinity is an elusive and ambiguous phenomenon that can manifest itself in many different ways in different contexts. This study focuses on the emergence of masculinity within the psychodynamic psychotherapeutic situation, with a focus on how masculinity is experienced. Both patient and therapist carry notions and experiences of masculinity into the therapy room. In addition, the psychotherapeutic situation, in itself, can evoke notions of gender. Sometimes masculinity can be the focus of the therapy, which previous research to some extent has drawn theoretical attention to, with a focus on certain aspects. However, there is a need for an empirical holistic approach to how masculinity is manifested in psychotherapy.The purpose of the dissertation is to clarify the meaning of masculinity, as it appears in the psychotherapeutic situation. This purpose is answered by empirically describing how masculinity is experienced in psychotherapy from two perspectives – the patient's and the psychotherapist's. The study is based on 27 in-depth interviews which were analyzed using a phenomenological method. The result is presented in the form of two meaning structures; one for the patient's experience of masculinity and another for the psychotherapist's experience. Finally, these two meaning structures are compared, in order to highlight common features and differences.The study shows that the patient's experience of masculinity is primarily rooted in the patient’s lived, first-person perspective, while the therapist's experience to a greater extent is constituted by a second- and third-person perspective. Both patient and therapist symbolize and conceptualize masculinity through different levels, where they share a bodily and a ”taken-for-granted” dimension. Their conceptualizations differ in that the therapist also has access to a theoretically informed perspective. Both patient and therapist constitute masculinity in a normative way; for the patient, the normative dimension is perceived in terms of ego-syntonic and ego-dystonic masculinity ideals and norms, while the therapist defines masculinity as either a positive or a negative phenomenon.A distinctive aspect of the result is, that masculinity can appear in terms of suffering for the patient or in terms of masculinity issues for the therapist. The masculinity suffering/masculinity issues can be associated with a polarized or immature form of masculinity, which – in the context of therapy – can undergo changes until appearing in a non-polarized, mature way. Another type of masculinity suffering, is when the patient does not feel in contact with masculinity. The result describes a changed masculinity experience in terms of a changed masculinity narrative, which can undergo three different elements; the prefigurative ground, the configurative processing, and the refigurative gestalt of masculinity. The study also sheds light on how the patient and therapist relate to one another in the light of a changed masculinity narrative.The comparative analysis shows that masculinity can be attributed with divergent meanings within the psychotherapeutic situation, and also includes a developmental, therapeutic and normative dimension. One conclusion is that masculinity has two sources of meaning; one lived and one theoretical origin. The lived perspective is linked to the life world, while the theoretical perspective has the potential to elaborate and broaden the life world experience of masculinity.
|
|
| 10. |
- Wagner, Nils, et al.
(författare)
-
Deep learning-enhanced light-field imaging with continuous validation
- 2020
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Light field microscopy (LFM) has emerged as a powerful tool for fast volumetric image acquisition in biology, but its effective throughput and widespread use has been hampered by a computationally demanding and artefact-prone image reconstruction process. Here, we present a novel framework consisting of a hybrid light-field light-sheet microscope and deep learning-based volume reconstruction, where single light-sheet acquisitions continuously serve as training data and validation for the convolutional neural network reconstructing the LFM volume. Our network delivers high-quality reconstructions at video-rate throughput and we demonstrate the capabilities of our approach by imaging medaka heart dynamics and zebrafish neural activity.
|
|
